This guy looks like fun...

[jabberwock]

It swims constantly until it finds something to grab onto and then makes a mucus house. I put a tiny snail in with it, and it attacked it immediately. Edited to add that when it swims straight, it has a ripple body movement. Thanks for looking.

 

[jabberwock]

27 views and zero guesses.

BUMP

 

[vetteguy53081]

It swims constantly until it finds something to grab onto and then makes a mucus house. I put a tiny snail in with it, and it attacked it immediately. Edited to add that when it swims straight, it has a ripple body movement. Thanks for looking.

Looks like a Sigalionidae worm

 

[((FORDTECH))]

27 views and zero guesses.

BUMP

Following to find out myself

 

[jabberwock]

Looks like a Sigalionidae worm

Yep, I think that is it. Thank you, I assume a bad guy the way it went after that snail.

 

[Pneumatic_Addict]

Following.

 

[vetteguy53081]

Yep, I think that is it. Thank you, I assume a bad guy the way it went after that snail.

Yes, predatory