I have a Halloween and a blue tuxedo. They blend in sometimes. It's sad though, my Halloween urchin is growing and loves nori, the tuxedo is shrinking, I can't get it to eat nori.I have no problem finding them, though I’ll definitely try out the hats. They’re big purple lunkers. This one is actually slightly smaller than the other one have.
They grow/shrink due to availability of their food source.