I have a large chalice that the other day I noticed had a cerith snail shell ( could be a hermit crab) under its skin spanning between two mouths.

3ec2711ae446855dd80948cc9048140b - Feeding chalice

Then yesterday I see it laying on top

10598abee98e5c132d0fc99261b1b932 - Feeding chalice

So I moved it and find a nice hole! (Not) I hope it heals!

c1fc5531cab7f49cfe27b7f73f669dde - Feeding chalice

Sorry for the bad pic they were taken from my iPad.