Can anyone tell me what coral this is?
 

I feel like I've seen it before but can't figure it out it randomly started growing off of my Xenia frag, anyone know what it is?

They look kind of like aiptasia to me. :thumbdown

http://www.xtalworld.com/Aquarium/hitchfaq.htm

that is aiptasia. its a nuisance anemone that will start to take over your tank. they are reallly annoying. you can buy stuff to treat it that is coral safe. or you can try and suck it out of your sand bed if possible.

buy a few peppermint shrimp to take care of any babies that my sprout up. to remove the larger ones just use aiptasia X directly into the center of polyp

Aiptasia. Not a good coral to have.

This is exactly what I did/am doing to rid of aiptasia. Haven't seen any except a couple in the bottom of my overflow in about 6 months. I've never seen my peppermint eat an aiptasia but I don't see any sprouting up in the tank so he must be gobbling them up before they can grow.

I wish I can find some peppermint to eat aiptasia. The ones I buy never seem to like it.......:(

Is there a specific place or species that has a higher possibility of eating them?

I don't think there is any rhyme or reason to which peppermints will eat aiptasia. I think that if they don't have a ton of food then they will probably have a higher chance of eating aiptasia, but like I said I have never actually witnessed a peppermint eating one.

any use of a non obligate predator will always be a hit or miss affair ;)

Ya I have never seen or had one that would eat them. Same goes with CBB, I have had a couple and none of them would eat them either.

Lemon juice and a needle is all you need for apstasia. Fill the needle with the lemon juice stick him with the needle and a squirt of the lemon and it should be gone