Good or Bad???

[all4wheels2]

I have several of these on this one rock and the "branches" have been growing recently. What are they? Is it an animal or marine plant?

Description: it's the brownish/red cone shapes with little branches and leaves coming out.

 

[hiltymj]

Just looks like some greenery on the rock I'm not an ID expert but I think it's fine. I had it on my rock but after I put my tangs in they ate it all

 

[Ricksreef]

Some type of kelp probably.