What kind of worm is this?

[Rendos]

My wife found this today in her tank. It is flat, black, and has a strange pattern on it's head. It can stretch out to over a foot in length.
Here are a few pictures...

 

[sl-atl]

Very cool! Looks like some kind of nematode worm based on the shape of the head, and the body texture.

 

[cloak]

Ribbon worm. I've had that exact same worm in my tank for years. Probably only see it about twice a year. Out of sight, out of mind.

http://home2.pacific.net.ph/~sweetyummy42/hitchworms.html

 

[Lmecher]

eeeewwww! That thing would scare the **** out of me, guess I am just being a girl but yuck!