Slug, or something else?

[mk3guy]

Found on the plastic upright of one of my zoa frags. Noticed it at night, went back this morning and there were two. I tweezed them out so I could get a better look. Noticed another couple moving up the rock to where the first two were removed from. Seem to only be on this one zoa frag, bypassed another zoa to get there.

 

[EeyoreIsMySpiritAnimal]

It's really hard to tell from the photos, so this is just a stab in the dark, but look up "bubble snail" or "Bulla Occiddentalis" and see if that looks familiar.

 

[mk3guy]

I know, the pictures are awful, but I couldn’t get mor focus. I will take a look