what is this thing!???? hitchhiker

[richiewwhite]

I recently bought some small peices of rock from petswarehouse since they had mushrooms on it and i got this weird thing I tried looking for it on hitchhiker links but i ont know what to look for

sorry for the image quality the tip of it opens up like a little circle and if you touch it with somthing it retracts away pretty small too. nothing has come out of it yet but i keep watching. these pics are at first light if it gets bigger ill take more pics i have no clue what the hell this thing is it isnt hard but its not to soft its like firm but moves no shell to it it looks kind of like it has a skin like a pineapple but more fine It is attached to the rock at the base


so let the guessing begin the only thing i have ever seen that looks similar is those like big cucumber looking things that have stuff coming out the top like a sea apple i think it was called/ but this is tiny and nothing out the top yet

 

[aaron23]

my guess is some kind of carnation

 

[noodleman]

looks like a tunicate to me aka sea squirt

 

[crox99]

A sponge?

 

[Timbo]

I am going with sponge.