Anyone know what this is?

[Quoiasdad]

Anyone knows what this is?

 

[StartingATank]

Flatworm, I believe

 

[saltwaterfish.com]

Definitely a type of flatworm, not sure which species however. Keep an eye out for any that look like they might be disturbing your corals.

 

[exnisstech]

I agree that it's some type of flat worm. Maybe @ISpeakForTheSeas can help out with an ID

 

[ISpeakForTheSeas]

I agree that it's some type of flat worm. Maybe @ISpeakForTheSeas can help out with an ID

I would guess a Prosthiostomid flatworm; not a keeper:

Prosthiostomid flatworm of some variety - they're predatory toward inverts and sometimes corals.