Looks like a slug. Good or bad?

Was about to dip this coral in this rock (dip whole thing) and saw what looks like a slug. Dip will kill it so wanted to see if I should save it before I dip.
Anyone know what this is? I'm kinda of in a time crunch cause can't stay in the bag for a long time

Thanks!!!

 

possibly a type of sponge. I have had some that have that texture but was bright yellow

 

Is it moving?

I have seen similar yellow sponges that you are referring to, mdBostwick. I have a feeling this thing is moving...

 

Yes it moved. I touched with my finger and moved a little. Looks like it has a tail. I have to take kids somewhere real quick so it's back in the bag. I'll check it for movement but do think it moved.

 

Are all sponges good?

 

it's something alien

 

If it moved i doubt it is a sponge. I myself would remove it, but I remove anything i can't ID and then ask and if it was beneficial just count it as a loss i didn't have to purchase.

 

Just a follow up. I dipped it and it came off and shrunk into nothing. A tiny little shriveled up something. Freaked me out.
I tried to get it off but wouldnt let loose. My bag was leaking and running out of time. So I dipped to take my chances. Glad I did. I would assume it was safe but not taking a chance.

That's that cool and weird part of hobby. Things grow in the tank. I saw something in my tank tonight haven't seen in months. Was a snail but haven't seen one in a long time. Boom they just show up

 

There's the snail on bottom of overhang. Think that's a turbo snail. I haven't seen one in easily 4 months. Then there it is.

This is not what I was asking about above. Just mentioning how things show up after a while once they grow