Would You Eat This Caterpillar's Face?
At the beginning of April, Which? magazine published the results of a blind taste test of 9 different caterpillar cakes. They assembled 75 tasters, 72 caterpillar cakes, and determined that Waitrose’s Cecil was the best-tasting one with 78% of the votes. Colin, the OG caterpillar cake, scored only 64%, finishing last.
Waitrose Cecil – 78
Co-op Charlie – 73
Sainsbury’s Wiggles – 73
Aldi Cuthbert – 72
Morrisons Morris – 72
Asda Letty – 68
Lewis & Green caterpillar celebration cake – 67
Tesco Slinky – 66
M&S Colin – 64
If you’ve never lived in the UK, you’re probably asking yourself right now: WTF is a caterpillar cake? While the designs vary, caterpillar cakes are typically chocolate sponge roll cake filled with chocolate buttercream, covered in a milk chocolate shell and decorated with sugar-coated milk chocolate buttons. Its feet and face are made out of white chocolate. M&S introduced Colin in 1990 and it became the staple cake for any type of celebration: from children’s parties to office birthdays to weddings.
Yet it still took more than two decades for the dupes to pop up: Sainsbury’s launched Wiggles in 2011, Waitrose launched their caterpillar cake (not yet named Cecil) in 2015 and Tesco launched their free-from version, Carl, in 2015. Then, Aldi’s Cuthbert came out in 2019. M&S sued Aldi in the High Court, arguing that Cuthbert copied Colin’s look and name and that Aldi was riding on the “coat-tails” of M&S’s reputation, which would confuse shoppers. It was settled in 2022.
This was a big story in the UK because it raised the question: when does a supermarket “dupe” become a legal copy? It also highlighted how strongly consumers associated the caterpillar cake shape with M&S, even though other supermarkets had their own versions. So when Which? blind-tested caterpillar cakes 2026, including versions from all major supermarkets, the issue of dupes did not even come up.
That makes caterpillar cake dupe economy weirdly interesting. In most categories, a dupe carries a social cost. It signals that you prioritised your wallet, that you couldn’t afford the real thing, or that you’re a savvy shopper by getting a dupe that does the very same thing, instead of splurging on the original.
In the food category, this can also backfire. When Aldi released a chocolate bar in the same distinctive unequal-chunk format as Tony's Chocolonely a few years ago, it flopped. Not because it tasted bad, but because Tony's meaning lives entirely in its brand: the mission, the supply chain transparency, the deliberate shape designed to represent inequality in the cocoa industry. Aldi’s version removed the meaning and that just left a chocolate bar in an interesting shape.
The caterpillar cake dupe works because the opposite is true. Remove the brand, swap Colin for Cuthbert, or Wiggles, or Cecil, and what matters is still there: the elongated chocolate body, the face, the sweets along the back, the ritual of awarding the face piece to whoever the occasion is for. These elements don't belong to M&S. They belong to the cake category. And over the course of 36 years, the caterpillar cake has become something closer to a tradition than a branded product. That’s exactly what M&S discovered when they sued Aldi over Cuthbert in 2021. The internet rallied behind Aldi because the lawsuit felt like a corporation attempting to ringfence the caterpillar cake. But by that point, they tried to claim ownership of something that was no longer theirs.
The reason the format carries all the meaning, rather than the brand, comes down to the face. The face is what makes the caterpillar cake a character rather than a product. And unlike products, characters exist in genres. Cuthbert isn't a Colin imitation in the way that the L'Oréal Paris Colour Riche "Worth It" is an imitation of Charlotte Tilbury’s Pillow Talk lipstick or the way the Target Birkin imitates the Hermès Birkin. He's a different character in the same story, the way there can be multiple fictional detectives without any of them infringing on Sherlock Holmes. The genre is open access.
Britain encodes class into food with almost no self-awareness. The supermarket you shop in, the tea you drink, the sauce you put on your chips. All of it is being read, continuously, by everyone around you. Most food products are legible status signals whether their brands intend them to be or not.
When I analysed YouScan social listening data, I saw that the rivalry between supermarket caterpillar cakes has evolved into a technical and social assessment that goes far beyond a simple preference for one brand over another. While Marks & Spencer remains the benchmark for quality, consumers now evaluate rivals using a specific set of criteria, focusing on the ratio of buttercream to sponge and the structural integrity of the chocolate coating. A particularly intense point of discussion involves the permanent decorative features, such as the chocolate faces and feet, which are scrutinised for their aesthetic quality and taste. Beyond the flavour, the choice of cake has become a form of social signalling. In online discussions, opting for a budget supermarket alternative is often framed as a lack of effort, leading to surprisingly harsh judgments about a host’s or parent’s commitment to a celebration. For many, the cake is a mandatory ceremonial object where the thickness of the chocolate shell or the size of the sponge, serve as a measure of the occasion's importance.
This made me wonder: why has nobody successfully premiumised it?
Because they haven't. This is strange when you consider what's happened to almost every other beloved, slightly naff British food in the past two decades. The sausage roll went from Greggs staple to object of serious culinary attention. The scotch egg became a gastropub centrepiece. The conveyor belt of British food culture runs in one direction: something starts cheerful and cheap, gets noticed, gets elevated, gets premiumised, gets expensive. The caterpillar cake has never once stepped onto it. There is no artisanal version. There are no caterpillar cakes with a single-origin chocolate face, hand-finished, selling for £30 at a farmers' market.
A beautifully made, seriously priced, artisanal caterpillar cake would make the occasion read as important, and making occasions read as important adds sincerity. The British celebrate things while keeping one eyebrow slightly raised. The caterpillar cake, at any of its price points from Iceland's £4.50 to Colin's £9.50, never claims to be fancy. It shows up. It does the job. The face does the emotional heavy lifting while giving everyone plausible deniability about having feelings. Premiumising it would remove the deniability, and the deniability is the product.
This is also why the Which? results are so interesting. Cecil tastes better; it’s richer chocolate, better sponge, more grams per pound spent. Cecil belongs to Waitrose, the most posh encoded supermarket in Britain. And yet in the blind test, stripped of every social signal, Cecil wins on the one metric: taste. But the caterpillar cake has never really been about taste. Colin, meanwhile, keeps selling over a million units a year on the strength of something no taste test can measure: 36 years of accumulated meaning, held in place by a chocolate face and a category that has refused to become anything more premium than it already is. It turns out that the refusal to premiumise is exactly the point.
