In the tale of The Very Hungry Caterpillar, along with an ice-cream cone, a pickle, a slice each of Swiss cheese and salami, a lollipop, a wedge of cherry pie, a sausage, cupcake and a slice of watermelon, our ravenous protagonist devours a piece of chocolate cake. It is perhaps no coincidence that the latter has become synonymous with the insect (and visa versa), and subsequently that a caterpillar-shaped sponge is often the most familiar guest at birthday parties and office celebrations across the land. Nor is it surprising that the news of Marks & Spencer taking Aldi to court in a bid to protect its Colin the Caterpillar cake has provoked such an uproar. The retailer has accused the discounter chain of riding on its reputational coat-tails after Aldi began selling its own Cuthbert the Caterpillar cake, which looks very similar. But since M&S launched Colin (a chocolate-coated sponge cake bearing buttercream, topped with sweets and fronted by a smiling white-chocolate face) some 30 years ago, similar critters have emerged, and not only from the German discount store. From Cuthbert and Wiggles to Curly and Carl the free-from caterpillar, there are cute-faced chocolate Swiss rolls in almost every supermarket – and each has a band of fervently loyal supporters. But how do they compare to each other? Does Colin hold the gold standard when it comes to softness of sponge and flavour of edible boot? Are the sprinkles on Curly superior to those adorning Morris? While Aldi has not stocked its Cuthbert cake since mid-February and so was sadly unavailable for review, we netted the best of the rest and put them to the test.