Wiwaxia was one of the weirdest of all the oddball animals of the Burgess Shale. It had a foot like a snail, a shell like a limpet, and scales like a fish on its shell. And the weirdest of all is that it had twelve glowing spines sticking out the top.
Wiwaxia may be weird, but there are many other weird animals in the Burgess Shale, like Amiskwia, Anomalocaris, Opabinia, Waptia, Leanchoilia, and Kerygmachela.
Wiwaxia was about 1" and vulnerable to many of the odd predators in the Burgess Shale, like Anomalocaris. It had to have a defense that would definitely fool a predator of thinking it's more dangerous than it really was, which was its glowing spines.