It was a hitchhiker on the live rock I don't know if I should keep it or get rid of it . It hasn't moved since I put the rock in the tank about 2 months now.
Looks like a Ricordea. Look at the cone that forms the mouth. If it's completely smooth-sided it's a Ricordea florida. If it looks like there are small tentacles on that cone it's a Ricordea yuma. Same genus but different species. Both are nice though.