What is this coral on my new live rock?

Hello I just got some live rock for my new 20gallon long reef setup and am very new to corals. I have been trying to ID this all night and can not figure out what it is, or if it is even a coral. When I purchased the live rock the guy I get it from said I will pick out some ones with corals on them so you can get some free corals and he said this was one of them. The other rocks had polyps and gorgonians so I am assuming this is a coral too.

It looks like tiny little brownish purple worms sticking out of it, here is a close up.

 

Unfortunately those are not coral but hydroids.

 

thank you