One of my E's, Pluto, seems to be an oddball when it comes to shells. He started off in an awful painted one. His first change with me was into a cassis shell, which I put in the tank as an "eh, maybe they'll like it" experiment. I've never heard of any crabs wearing them, but he immediately took that one weird shell out of the bunch.
Tonight he changed into a Rapana shell, which I've heard most crabs don't like. However, my little weirdo looks very handsome in his new shell and he's been showing off to the other crabbies.

You can also see how he modified the inside of the cassis.
