What is this?

[Jus]

Can anyone tell me what this is?
Setting up a tank and bought some rock and this was in with it

 

[NY_Caveman]

Looks like a lot of life in the rock. That is some kind of worm and does not strike me as a dangerous one.

#reefsquad may be able to provide an exact ID.

 

[Crabs McJones]

Sponge I do believe

 

[MSB123]

+1

Sponge I do believe

 

[saltyhog]

Wow, I never would have guessed sponge. Is that morphology common?

 

[cristata.reef]

Big peanut worm, note the bands on the tail and the enlarged "head"

 

[reef lover]

Yup big peanut worm...

 

[Jus]

Good or bad?

 

[NY_Caveman]

Not bad at all. Good CUC.

 

[Jus]

thanks everyone for your help