My daughter says it's a sea snake

It actually kind of looks like a sea snake lol.

Does it swim or crawl? Catch it if you can. It will make taking pictures a lot easier and you can hold it pending identification.

 

Does it have a distictive head/face??

 

I think its a ribbon worm

http://www.saltcorner.com/sections/zoo/inverts/others/worms/Bhemprichii.htm

 

Phoenixhieghts hit it on the money... its a ribbon worm...

 

Great ID

:grinthumbs:

 

I was gonna say ribbion eel
kinda impossible though

 

Why impossible?? Eels - - Blue Ribbon eel (Rhinomuraena quaesita)

 

That almost looks like a giant tube anenome that came out of its tube.

 

Ya that does look kinda like a ribbon worm although it's possible it's still something else, I would try and get it out of the tank and put it in a jar or something for a better photograph and if it really is, probably toss it. Doesn't sound safe to me.

Great ID though Phoenix, there are so many worms out there it can be tough.

 

gross... nuke it!