Best caterpillar cakes: Colin vs supermarket rivals

Marks and Spencer's Colin Caterpillar cake has been invited to many British birthday parties for more than 30 years, but is it time to start inviting other caterpillars to your celebrations?

From Slinky to Cecil, plenty of other supermarket alternatives now get a slice of the action.

Co-op's is one of the priciest of the bunch, at £9.85, while Iceland's caterpillar cake is just £4.50, offering a decent saving if you're after a cheaper way to feed the party. But is it worth paying more? 

To find out which caterpillar cake reigns supreme, we asked a panel of consumers to rate nine different options in a blind taste test. We tested an army of 72 caterpillars, and each cake was tasted 75 times in total (and yes, it was as delicious as it sounds). 

Best caterpillar cakes

While the overall design varies, all the caterpillar cakes typically consist of a rolled chocolate sponge filled with chocolate-flavoured buttercream, and covered in a solid chocolate shell. 

In our taste test, Waitrose's Cecil came out as the best caterpillar cake, earning himself a Best Buy with a cracking score of 78%. Iceland's cake is a Great Value option, costing just £4.50.

Best Buy: Waitrose Cecil Chocolate Sponge Cake - 78%

£9.50, serves 12

Weighing 744g, Cecil is the biggest caterpillar cake we tested, so although it's more expensive than most overall, it's actually one of the cheaper cakes by weight.

Most of our tasters were satisfied with the strength of the chocolate flavour, the sweetness and the thickness of the chocolate shell.

The sponge's texture was spot-on, and the tasters enjoyed the soft buttercream, which had just the right amount of sweetness. Just under 70% of the tasters said the sponge-to-buttercream ratio was perfect, too.

Achieving the ultimate combination of rich chocolate flavour, moist sponge and soft buttercream is no easy feat, but Cecil scored top in almost every one of our measurements. That in itself is worth a celebration with Cecil!

Available from Waitrose.

Co-op Party Time Charlie Chocolate Cake – 73%

£9.85, serves 12

In joint second is the Co-op Charlie caterpillar cake. While it's the priciest caterpillar on our list, it's also on the larger side, weighing 702g.

Our tasters said the sponge was delicious and the chocolate flavour spot-on, without being too sweet. Charlie missed out on our top spot because some of our tasters found the sponge a touch too dry, but the delicious buttercream more than makes up for it. 

Available from Co-op (in-store only).

Sainsbury's Wiggles the Caterpillar Cake - 73%

£8.50, serves 14

Joining Charlie in second place is Sainsbury's Wiggles. 

Wiggles is one of the most similar-looking caterpillars to Colin, so if you're keen for a lookalike, it's a good bet. While it's a tad cheaper than our Best Buy, Wiggles is a bit smaller than his peers, weighing 613g. He serves up to 14 people, but you may get a smaller slice than with Cecil or Charlie. 

Our tasters enjoyed the chocolate flavour and the thickness of the chocolate shell. The only thing we had to mark Wiggles down on was the sponge, which some of our tasters said was a touch too dry.

Available from Sainsbury's.

Aldi Cuthbert Caterpillar Cake - 72%

£6.99, serves 12

In joint-third place comes the world's most infamous caterpillar (bar The Very Hungry Caterpillar, maybe?) – Aldi's Cuthbert. 

After the 'Free Cuthbert' campaign in 2021, Cuthbert is now one of the most recognised caterpillar cakes. He weighs 624g and serves 12 people, so about the average.

Our tasters said that the chocolate flavour was just the right strength and sweetness. The texture of the buttercream was also lovely and creamy, which balanced nicely with the sponge-to-buttercream ratio. The only thing Cuthbert could improve was the sponge's texture, which a third of the testers found too dry. 

Available from Aldi.

Morrisons Morris The Caterpillar Celebration Cake - 72%

£9, serves 12

Also in joint third is Morrisons' Morris Caterpillar Cake. Morris contained the least sugar per 100g (38.4g) among those tested. It serves 12 people and weighs 630g.

Getting the top score for buttercream texture and the second highest for chocolate flavour, this cake was really popular with our tasters. The sponge texture was a little dry, but the buttercream-to-sponge ratio was spot-on, so it more than made up for it.

Available from Morrisons.

Discover our taste test of hot cross buns, along with thousands of other reviews and advice: join Which? today

How the other caterpillar cakes scored

Our taste test suggests you can't go too far wrong with a caterpillar cake, with all the cakes scoring at least 64%. A dry sponge was the main problem across the board, but for the lower scorers, the chocolate flavour and buttercream let them down a little.

• Asda Letty The Caterpillar Cake – 68%. While Letty had a nice thick chocolate shell and a good chocolatey flavour, 40% of our panel said it had too much buttercream, and more than 60% said the sponge was too dry. £9, serves 12. Available from Asda.
• Great Value: Lewis and Green (Iceland) – 67%. Iceland's Lewis and Green Caterpillar Cake is our Great Value pick. It's the cheapest by a mile at £4.50; the only caveat is that it's also the smallest, at 530g. It has a lovely, moist sponge and delicious buttercream. A downside is that the chocolate layer is a bit too thin, and the chocolate flavour could be stronger, but for the price, you can't really go wrong. But Iceland, please give the poor caterpillar a name! £4.50, serves 10-12. Available from Iceland.  
• Tesco Slinky Caterpillar Cake – 66%. Tesco's Slinky Cake had excellent chocolate flavour with just the right amount of sweetness. Its buttercream was pretty good, too, but nearly half of the panellists found the sponge too dry. £4.50, serves 10-12. Available from Tesco.

M&S Colin The Caterpillar Cake - 64%

£9.50, serves 10-12

Colin the Caterpillar is one of the most famous caterpillars around. That's why we were surprised at its ranking in our testing. While 64% isn't a score to be sniffed at, we did reach out to M&S to see if it had any comments.

M&S said:

‘Colin the Caterpillar is the UK’s number 1 caterpillar cake – over a million are sold every year. He has been named the nation’s best caterpillar cake in an independent YouGov poll.* 

'Made and finished by hand in the UK for over 35 years, it leads the market on quality and taste. It has the highest chocolate content on the market, at 39.5%, with milk chocolate made from 31% cocoa solids and 100% Fairtrade cocoa. 

'At M&S, blind-taste testers regularly taste our products against the market to ensure we remain number one for taste and quality – this includes our Colin cakes, which consistently come first in taste tests.’ 

*Data that ranked M&S Colin the Caterpillar first is from YouGov Plc. Total sample size was 2,122 adults. Fieldwork was undertaken between 27 and 30 March 2026. The survey was carried out online. The figures have been weighted and are representative of all UK adults (aged 18+).

Our panel enjoyed the thickness of the chocolate shell and the texture of the buttercream. But 44% said the sponge was too dry, and 40% said the chocolate flavour was too weak. Colin also had the highest sugar and fat content of the cakes tested here (46.3g of sugar and 21.3g of fat per 100g). Also, for the price, he isn't as large (625g) as Waitrose's Cecil or Co-op's Charlie, which are similar prices. 

While Colin missed out on the top spot, it's still one of the most popular supermarket caterpillar cakes around. If you're feeding a crowd of Colin fans, you may want to get your hands on M&S's Giant Colin the Caterpillar Cake, which serves 40 people and costs £50. You can also get it personalised with a message of your choice. 

You can also get Mini Colin the Caterpillar Cakes, if you're not feeling as ravenous as The Very Hungry Caterpillar. 

If you're considering branching out from Colin, M&S also sells Connie the Caterpillar, who is decorated with sugar hearts and has pink chocolate feet. 

Available from Ocado and in-store at M&S.

Fancy a frozen Colin? Check out our review of the icy Arctic Colin cake

Vegan and Free From caterpillar cakes

None of the caterpillar cakes we tested are suitable for vegans. If you're after a dairy-free or gluten-free version, several supermarkets offer 'free from' and vegan options. These include:

• Sainsbury's Free From 'Eric the Caterpillar' cake, £8.50 for 557g. Available from Sainsbury's
• M&S Made Without Wheat Gluten Free Colin the Caterpillar, £9.50 for 655g. Available from Ocado and M&S
• Tesco Free From 'Stripey the Caterpillar' cake, £7.50 for 600g. Available from Tesco
• Lazyday 'Mini Vic the Vegan' caterpillar cakes, £3.80 for 160g. Available from Morrisons

Fancy baking your own cake instead? See our reviews of the best stand mixers, the best cake tins and the best kitchen scales

Do caterpillar cakes contain palm oil?

All the caterpillar cakes we tested contain palm oil. The supermarkets in our taste test state that they use only responsibly sourced palm oil. Most use RSPO-certified palm oil, which is certified as sustainably produced under the RSPO scheme.

Full results

How we tested caterpillar cakes

The caterpillar cakes were taste-tested in early March 2026 by a large panel of consumers who enjoy this type of celebration cake. The panel broadly reflects the demographic profile of adults across different age groups in the UK. 

Each caterpillar cake was assessed by 75 people. Tasters rated the taste, texture, aroma and appearance of each product, and told us what they liked and disliked about it. 

The taste test was blind, so people didn’t know which brand they were trying. The order in which they sampled the caterpillar cakes was rotated to avoid any bias, and each person was in a private booth, so they couldn’t discuss what they were tasting or be influenced by others.

The overall score is based on:

• 50% flavour
• 30% appearance
• 10% aroma
• 10% texture

Tasters rated the overall visual appeal of the cakes separately from tasting a slice.

Prices and availability information last checked March 2026.