what is this

[j_hammer]

i found this little guy in a tub of rock that i am holding for some one, what is it, is it good of bad to have in reef tank.
http://i499.photobucket.com/albums/rr359/j_camaro/P1250900.jpg

[noirsphynx]

That's some kind of flatworm and flatworms are typically not reef safe.

[j_hammer]

he is about 2-3" long and 1".