What the heck is it?

[Dallas]

OK, ya'll. Need your expertise - yet again. I spotted this guy cruisin' the tank a few month's ago and never saw it again - actually thought I might be seeing things. This time, I was able to get a picture. He's a good hider, blends in easily with the rock and apparently likes snail for dinner. What is it?

[greeneyes]

Flatworm, do a search on here and you will find the info you need.