What animal is able to make itself a vegetable by eating it's own brain?

I know a certain animal exists like this, but I need to find the exact animal. I'm not talking about the scientific name or anything, but at first I thought it was a sea cucumber, but then researched and found sea cucumbers have no brains...*grins* But I THINK it's a sea animal. So, can anyone help me out?|||i think you might be thinking of a tunicate (sea squirt). they start off as a tadpole-like larva, then plant their heads in the ground once they've found a good spot. after that, their brains and other organs degenerate and for the rest of their lives, they mindlessly siphon water for nutrients. they're actually chordates (like humans), believe it or not. it's only obvious in their larval state though.|||It maybe a starfish,jellyfish or a kind of animal(anything) that has a soft body,mostly invertebrate|||How can someting eat it's own brain???|||I have searched and searched, can't find anything on that.|||#4 has the correct answer, but I just wanted to add I know a lot of people like that too!! :-) I think it comes from watching daytime TV