Colin the Caterpillar and the Art of War – why it is sometimes sensible not to enforce your legal rights

17th April 2021

Marks and Spencer has decided to add to the gaiety of the nation by issuing a legal claim in respect of Colin the Caterpillar, a chocolate cake.

The actual legal claim does not appear to be publicly available, but the news reports are that the action was launched in the last week at the high court.

Marks and Spencer is quoted as saying:

“Love and care goes into every product on our shelves. So we want to protect Colin, Connie and our reputation for freshness, quality, innovation and value”. 

It must have seemed a good idea at the time.


Hilarity has ensued.

The respondent to the claim, Aldi appears not to be taking the legal threat seriously.

And nor are many people on Twitter and other social media.

This mash-up of our old friends at Handforth parish council stood out in particular:


This has all the signs of a publicity disaster for Marks and Spencer.

So why did Marks and Spencer issue the claim?

And what should the company have thought about before bringing the action?


There is no doubt that Colin the Caterpillar is valuable to Marks and Spencer.

The product has recently celebrated its thirtieth birthday.

And Marks and Spencer have been long aware of competitors’ selling similar products, with the store itself telling us this on its dedicated Colin the Caterpillar page:

“We were the first to retailer to sell a caterpillar, with many supermarkets since trying to emulate this crowd-pleasing cake”.

Colin also has his own Wikipedia page.

And not only does he have these pages, he also has registrations on the trade mark registry.

(Trade mark has two words, by the way – we are not Americans, thank you.)

From a quick (no-exhaustive) search, it would appear that the term ‘Colin the Caterpillar’ was registered in 2009 – though given it had been on sale previously it may have had other intellectual property protection beforehand.


This search also showed that last year in 2020 there was a further registration for Colin’s packaging:

The happy news can also be revealed that Marks and Spencer has also registered the term Connie the Caterpillar – though not her packaging.

All three registrations are in respect of class 30:

These registrations in practice and in principle confer a commercial monopoly in products within that class.

(Please note: although I have general knowledge of trade mark law, I am not a trade mark specialist, and there will be things I will have missed – and I am happy to hear from any trade mark specialists in the comments below.)

Here it is important to note that what is protected with these registrations is the name and the packaging of the cakes – and not the cakes and their ingredients themselves.

Colin the Caterpillar and his box are protected, not the concept of a chocolate roll with a happy face on it.


One of the problems with trade mark law and practice is, in very general terms, that if a protected thing becomes too generic, you can lose the legal protection.

That is why trade mark holders often seem over-vigilant in asserting their legal rights.

Disney for example will assert their rights fearlessly, despite the ridicule and opprobrium.

Readers of a certain age will also remember letters to the press from Portakabin.

No doubt Aldi itself has its own trade mark lawyers who will send out stiff letters to infringing competitors.

(Indeed there are marks registered to various Aldi entities that presumably they would want respected.)

And as Marks and Spencer itself admits on its own website, there are other stores seeking to ’emulate’ the Colin cake.

One tweeter helpfully provides us with examples:

As does another:


So: the commercial predicament of Marks and Spencer was as follows.

The company had a popular, valuable and distinctive well-established product.

This was a product that took expense to make and also to promote.

The product was protected with registered trade marks for both its name and its packaging (as well as, no doubt, other intellectual property protections such as ‘passing-off’.)

The company faced competition from other stores with similar products.

Some of these rival chocolate caterpillars had similar names and packaging.

What was a company in that position do?


Here we come to the old distinction between having a legal claim and asserting it.

In essence: just because you have a legal right, it does not necessarily follow that it should be asserted or enforced.

And if a decision is made to assert and enforce a legal right, you have to think through the implications and reactions.

Some companies like Disney will know there is a negative reaction to their enforcement of legal rights – but in such cases the cost-benefit analysis is that the rights are too valuable to lose to the public domain.

And such a robust approach is common in industries where the commercial value is largely in intellectual property.

A cartoon mouse and a portable cabin are not especially complicated things – so what is bought, sold and licensed is often the intellectual property of thing, rather than the thing itself.

And much the same can be said of a long chocolate roll decorated with sweets and icing.

One can imagine how the commercial and legal teams at Marks and Spencer knew that competitors with products with similar names and packaging was creating a commercial and legal risk.

It may well be Cuthbert today, but tomorrow it could be Colvin, and before they knew it there would be Colin the Caterpillars everywhere in every store.

And Colin the Caterpillar’s registration renewal was coming up in 2028. 

What else could they do?




They should have thought it through.

Presumably there had already been pre-action correspondence between the parties – it is rare for a company to issue a claim in the high court without setting out the case first in correspondence, and there are costs implications if a party does.

And presumably Aldi had denied the claim in correspondence.

Aldi thereby knew what was coming – and not only its commercial and legal departments, but also its media teams and external PR advisers.

Marks and Spencer do not appear to have issued a press release about the claim, but somehow, some way the media soon knew about the claim.

Perhaps this was because of a vigilant court watcher, or a tip-off from somebody, or even part of a media strategy: who knows.

But once the claim was issued at the high court, the dispute went from one set out in private and confidential correspondence between the parties – and into the public domain.

In essence: you lose control of the story.

And when the story is as media-friendly as about chocolate caterpillars called Colin and Cuthbert then there is a high probability that the media will become aware.

But from the news reporting it seems that Marks and Spencer have been caught unawares – while the Aldi press office is having a party with social media generally.

So the question has to be asked: was/is protecting the Colin the Caterpillar name and packaging worth it?

Unlike a cartoon mouse or a portable cabin, Colin the Caterpillar does not go to the heart of Marks and Spencer.

Had Aldi promoted an own-brand range of goods called, say, St Michelle then that would have been different.

And – and I defer here to trade mark lawyers – it may have been perfectly possible to renew the trade mark in 2028 even taking the (current) challenge of Cuthbert at its highest.


A view had to be taken on the risk of litigation against the risk of not litigating.

As the Art of War showed (and that is still the best practical guide to civil litigation) being able to attack is not the same as it being a good idea to attack.

Here one can ask McDonalds about McLibel – or the British Chiropractic Association and its illiberal and misconceived claim against Simon Singh.

And if the decision is made to litigate then a claimant must be prepared for what can happen next – in terms of commercial and media matters, as well as at law.

This is not to say that people and companies should not assert and enforce their legal rights – indeed, that is what legal rights (and lawyers) exist for – but that the decision to do so is always distinct and separate from being able to do so.


Declaration: as the blogger ‘Jack of Kent’ I helped co-ordinate the defence campaign in British Chiropractic Association v Singh and I practise in media law as a solicitor, although not in respect of chocolate caterpillars or supermarket stores.


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37 thoughts on “Colin the Caterpillar and the Art of War – why it is sometimes sensible not to enforce your legal rights”

  1. I will be mildly interested to see how much weight the UK courts give to similar cases involving Aldi in Australia, decided here by the Federal Court, when Aldi successfully defended complaints of passing off

    As nothing but an amused amateur, I also wonder how M&S’ admission that other chains have imitated the Colin The Caterpillar cakes affects the case. Surely that allows Aldi’s representatives to drag the argument into the weeds: why is OUR client’s cake in breach of M&S’ rights when you have ignored these other examples? What exactly is the difference?

    1. Looking at some of the photos above, it looks to me that Aldi have tried to exactly copy M&S – the faces look very similar to me, much more so than any of the competing brands. The others have different eyes and different antennae. Others have different patterns of coloured sugar-coated chocolate buttons on top (I’ll get in trouble for calling them Smarties®️), or different sweets altogether. In other words you could argue that the other supermarkets have been ‘inspired’ by Colin, while Cuthbert may actually be a copyright infringement.

      1. I see this resemblance too but it isn’t a duplicate, there’s a proximity matter worthy of thought but it isn’t being sold as M&S, or even a copy of, it being sold as a chocolate caterpillar. It seems, even in legal terms, very petty, unless M&S have seen a huge dive in sales & custom in general & Aldi has gained what M&S have lost, and this is somehow attributed to Cuthbert…. It’s all very funny & Aldi are certainly winning the hearts & minds, through making everyone laugh

    2. I tend to think their failure to pursue other competitors would harm an attempt at obtaining an injunction to restrain the sale of caterpillar cakes, but the trade mark infringement damages claim doesn’t hinge on whether they have pursued similar claims against competitors. Without seeing the claim we can’t know the precise remedy being sought.

  2. Aldi operate in a lot more countries than M&S and I don’t think they sell Cuthbert everywhere. I expect M&S will ask them why they only sell Cuthbert in places where Colin is known.
    I just came back from doing some important legal research and I can confirm that Cuthbert isn’t available in Aldi in County Clare, Ireland today (dunno if it is ever available here, and we do have a few M&S stores).

  3. M&S said (BBC News) “”So we want to protect Colin, Connie and our reputation for freshness, quality, innovation and value.”

    So are they claiming that Aldi’s version is cheap and nasty with poorer quality ingredients?

    I am great with ideas but not marketing – anyone out there with the ability to knock up packaging ideas for my new Colon The Caterpillar?

  4. I am not a lawyer, and don’t even play one on TV, but it seems that a consumer is not likely to be confused by a cake in Aldi being similar to one in another shop – so surely the is no case to answer for “passing off”?

    1. They are suing for trademark infringement rather than passing-off, if reports are correct. It is not always necessary to prove that customers could be confused in order to succeed in a trademark infringement claim.

      1. I’ve not seen the legal papers, and a trade mark specialist might want to chip in, but it seems to me that the Aldi product is plainly not using an identical sign to M&S, so an action for infringement under s.10(1) or s.10(2)(a) or s.10(3) of the Trade Mark Act 1994 won’t be available.

        So that leaves M&S with a claim for infringement under s.10(2)(b) – a similar mark, used with the same or similar goods, with a likelihood of confusion. I expect M&S will claim infringement in relation to both registered marks – both the name and the packaging.

        I can’t see how either trade mark will assist M&S once the cake is taken out of the packaging. But the Cuthbert product looks to me to be visually very similar to Colin, so I’d expect M&S to throw in “passing off” too (compare the Jif lemon case).

        Aldi is likely to point to the other retailers selling similar products in similar packaging under similar names, and may say that (a) the marks have become common in the market that they are no loner distinctive and have become generic (similar green packaging, “C[ ] the Caterpillar”), and (b) there is no confusion anyway, as almost no one (even an idiot in a hurry) would expect to find an M&S product one sale at Aldi.

        Trade marks come up for renewal every 10 years: as cylindrical chocolate caterpillar cakes in windowed green boxes are widespread, M&S may want to pre-emptively assert some distinctiveness for their Colin cake now.

        Given the extensive news coverage for M&S protecting their well-known product, M&S may see this as a PR win so far, but who knows where this will end up. Perhaps it suits Aldi to have some publicity for their cheaper imitations too.

        (Robert Rinder was discussing this claim on the television. I was very disappointed when he started talking about copyright.)

        1. To correct myself , s.10(3) (as amended) can apply where a mark is used in relation to any goods or services (identical or similar or not) if the mark is identical or similar to a registered mark with a reputation, and either takes unfair advantage of it, or is detrimental to it. Strictly speaking confusion is not required, although taking unfair advantage and detriment may cover similar ground. So there we go.

    2. It could at a Children’s party. The parent who bought Cuthbert would know. The guests and children could think its Colin (and may even be told as much) and get a negative impression of it as Aldi’s is drier.

      (Full disclosure no comment on Aldi in general. I tend to buy Aldi imitations, although generally good just more fat and sugar usually than originals but so much cheaper)

  5. I was previously unaware that Aldi purveyed a (no doubt cheaper) larva-style celebratory comestible, so this looks like excellent publicity for them.

  6. Or
    “You know that stuff they’re selling at the local shop? I Can’t Believe It’s Not Butter? Well I can’t believe it’s not butter. Then yesterday I went to Crookenden and I bought this other stuff, like a sort of home-brand, and I can’t believe it’s not I Can’t Believe It’s Not Butter. I can’t believe that both I Can’t Believe It’s Not Butter and the stuff that I can’t believe is not I Can’t Believe It’s Not Butter are both, in fact, not butter.”

  7. Somehow I can’t help but thinking “Streisand effect”. While not 100% applicable I still think it in a way applies. Before this probably only a limited number of people (mainly Aldi customers) knew that Cuthbert existed. Now a significantly higher number of people (incl all Law & Policy blog readers, at least some of which might not have been Aldi customers before) know of Cuthbert. And in a number of cases might decide that even if Cuthbert is of slightly less quality (eg more fat and/or sugar or it is drier) than Colin the cost savings is significant enough.

  8. Post sale confusion might be their best bet: so yes, the “at the children’s party” scenario sis a good one to run with I would think, when the cake will be out of its box.

  9. Back in the day, when I was growing up, what my mum mostly bought from Marks and Sparks were their cheap, own-brand versions of branded biscuits, named in a sort of reminiscent fashion. And I seem to recall a bit of a stooshie about one of them, (possibly Breakaway?, possibly a court case?). Ah, the irony……

  10. As a trade mark lawyer I would imagine that the following will be alleged:

    1. Likelihood of confusion
    2. Dilution and unfair advantage (and they will rely on the face as evidence that Aldi purposely chose to get so close that people would link it to M&S)
    3. Passing-off (when you see the cakes you are likely to think it’s the same cake if it is out of the box. The face is the biggest issue I think).

    If I were M&S I would also have alleged copyright infringement

  11. Personally I think United Biscuits (U.K.) Ltd v Asda Stores is still the nadir. An entire case based on the inability of the public to distinguish Penguins from Puffins. Not only was it ridiculous but, we now know, it set the chain of events in motion which led after twenty four years to litigation based on the names of caterpillar cakes.

  12. My feeling, without having seen the papers is that M&S will be relying upon more than their registered TMs (if the extent of their rights are fully represented in the article). Passing off alleging goodwill in the face is likely to be one of their ‘strongest’ arguments (I understand they have spin-off products which also use Colin’s face.

    Personal view on this case is as follows:

    1. M&S have showed restraint against similar products in the past, but this cake is more similar and probably is too close for comfort in their view.

    2. Actually, one might are argue that their inaction in the past has led to the present predicament and that had they been more litigious then their registered rights might have carried more weight.

    3. They will be relatively confident in their case, because it is Aldi on the other side. Aldi are well known for pushing their luck, as well as not backing down and for being v.good at the social media game.

    3. However, I do not necessarily see M&S losing the PR battle. Aldi do this regularly, their customers know this and I suspect quite like it. However, M&S also has a very loyal base and I suspect their customers will like the fact they are standing up for themselves.

    4. M&S’ biggest mistake in my opinion is not having registered the face. If they were expanding the range by keeping face as a key indicia, then they should have registered that as well.

    Harrison Lee, chartered TM attorney

  13. M&S “jaffa cakes” were surely a shameless knock off of McVities original as we’re most of their own brands copies of something else.

    I now that they haven’t tried complaining about Waitrose whose caterpillar cake is excellent.

  14. As a marketing consultant I suspect Aldi are playing a bit of a blinder here. On the basis that they will lose they’ve gained a huge following for Cuthbert, a following that will be largely maintained as they metamorphosise, with great (social) media fanfare into whatever new guise the courts deem necessary.

    Did anyone check Aldi’s recently Registered trade marks for alternative looking caterpillar cakes, or maybe even butterfly cakes?

  15. I’m current tooling up to make a pink, sugary, soft gelatinous confection, featuring porcine physiognomy, which I plan to sell in 100g bags in sweet shops.

    Consumer reaction in blind testing so far has been favourable, and following research into branding we have settled upon the name “Porky Pigs”.

    What could possibly go wrong?

  16. Are M&S and Aldi in fact ‘cooking’ it together to promote both their roly-poly cakes?

    As long as no cake flies away. Or no company thinks of producing a furry version.

  17. M&S makes the point that their cake is of superior quality. Why not then milk the PR opportunity and announce the arrival of Sir Colin The Caterpillar, knighted for 30 years of public service. Quick package redesign and a USP that leaves the others behind…..unless Lord Cuthbert emerges. Back to the drawing board!

  18. Wonderful commentary that put a smile on my face.

    Colin the Caterpillar Cake has been a family favourite several times a year now beginning 18 years ago. Colin must be saved yet l feel Cuthbert must be let out of jail. In times like these surely the more chocolate cake available is better to cheer us up as we object to this Johnsonian Governments next shocker.

    Hopefully the cakey going ons between M&S and Aldi will boost sales, although in my household Colin will not be toppled.

  19. As a scientist, rather than a lawyer, I put it down to the irresistible force of caterpillary action.

  20. I have some experience in IP, including TMs.

    10(2) will struggle I fear, due to the liklihood of confusion hurdle.

    British Sugar v James Robertson assessed similarity. It’s quite a hurdle, as the court looks at uses and users of the goods, trade channels where they are found on the shelf and how they compete. Seeing as an alleged infringing cake can only be bought in another store, unlike copy cat products on the same or similar shelf, confusion is a tall order.

    10(3) is possible, as confusion is not required.
    However, the use of a similar mark will cover some of the same arguments.
    Reputation and unfair advantage must be proved.

    Defences may cover non-use if M&S haven’t been defending the right previously or the fact that similar products have been for sale by numerous outlets for years would in my view make reputation and unfair advantage arguments tricky.

    I would assume passing off (United biscuits (Penguins) v asda) and copyright infringement as well as any registered and unregistered design rights may be thrown in too. United failed in its action for tm infringement, and went for passing off instead.

    I think that M&S ought to have been more litigious when competing cakes first appeared, to nip it in the bud then. To allow the competitors to make hay for so long may be an error.

  21. As the Art of War showed (and that is still the best practical guide to civil litigation)
    – dial it back Grandad, everyone knows that Clausewitz’ “On War” is the premier Civil Lit guide and the Art of War is just for auditors who can’t admit they work in a world of turgid boredom.

  22. I recall when I started at the Bar a very small shop in South London selling garden gnomes was sued by British Home Stores (of blessed memory) because it was called British Gnome Stores. Unable to take on a David and Goliath struggle, BGS avoided the litigation by changing its name to the National Elf Service.

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