Another unknown creature

[Turkey head]

Any idea what this creature is?

 

[KJ]

Nudibranch.

 

[Turkey head]

I think it's an encrusting sponge. I tried to get it and it didn't run. It was stuck to the glass really well but didn't seem to have a mouth. Appeared to be stuck to some pebbles too. I put it back. I decided it was a nudibranch which is why I decided to get it out but it isn't. I do have some sponge that is a similar color. No where near it though

 

[Mike N]

Weird, bump.

 

[Turkey head]

Not a good picture but this is what it looked like when I got it off the bottom and was holding it with big ol tweezers. Didn't try to get away or anything. Just sat there.

 

[Salty1962]

Looked like a sponge with Bristle worms underneath it.