Help ID this yellow stuff

I have several clumps of this stuff in my reef. Is it tunicates or sponges? Or alien snot???

 

sponge

 

He lives in a pineapple under the sea!

It's a sponge! Nice and bright yellow. Pretty cool stuff.

 

I thought alien snot at first

 

I have these guys all over my tank, as well as white, pink, purple, and see through ones too. I like them, but be careful to watch out for them. I had one grow in between two torch heads, and one of the heads died. coralline helped me out and told me they can use chemical warfare I removed the sponge and now the other head is doing great.

 

arent tunicates sponges?

 

no. I'm not good at explaining, but check this out

What's a Tunicate?