no it is not pom pom xenia...i am trying to think what it is...i saw a rock full of this at my lfs and almost bought it but decided ididn't have the room in my tank....if i find/think of what it is...i willlet you know...
its definatly not pom pom xenia pom pom is the first image
pulsing xenia is the second.
my guess is either glove polyp
or goniopora if it has a hard skeleton at the base I cant tell because of the algae.
could it be clove coral maybe? that name rings a bell for some reason...don't mark my word i am looking on my lfs's site to see ifi can find it but i believe they may have sold the piece since