Hitch hiker on hermit crab shell

[Angeljr8282]

been trying to ID this for while not even chatgbt could help….at first I thought it was just nothing on the shell but as time gone by I noticed it getting larger…..today I was cleaning the tank and noticed something coming out from under it look like a snails type head it was black in color.

 

[Sophie"s mom]

Possibly some sort of tunicate maybe

 

[Tahoe61]

Look up Slipper Snail or Limpet and see if that looks similar.