re-identification

[ThAtGuY11]

i recently posted this same thing but iv gone on holidays and its changed shape and i was able 2 get a decent photo of it. also i noticed that if i tap on the glass or close the tank cupboard it sucks itself into the rock leaving the small white circle the only thing you can see. its about 1.5 cm at the longest point.

 

[Devilishturtles]

Is it a hard tube that you can tell? What sticks out of it? Probably just a feather duster.