From New Scientist:
As the caterpillar of the moth Uraba lugens grows, it sheds its exoskeleton – but rather than getting rid of the previous head section, it stays attached to its body to create a bizarre "hat".
This has earned it the nickname the mad hatterpillar, after the Mad Hatter in Alice's Adventures in Wonderland by Lewis Carroll.
U. lugens moults up to 13 times while in its caterpillar phase, with the tower of heads starting to be built from the fourth moult. As the caterpillar grows, each empty head is bigger than the last.
The headpiece isn't just for show, however. "The function is to protect them from predators – they use it to bat predators away," says photographer Alan Henderson of Minibeast Wildlife, an invertebrate resource centre based in Queensland, Australia.
I know butterflies are the aspirational metaphor for most caterpillars, but maybe more of us should aspire to remain in our larval forms as long as we can wear our 13 empty old heads as hats. It's even more fashionable than those fancy butterfly wings!
Weird caterpillar uses its old heads to make an elaborate hat [Gigi Li / New Scientist]