Red flatworm good or bad?

[Technewb]

Just noticed these red looking flatworm tonight while looking in my sump. I did add some corals that i qt for 3 weeks and added some chaeto from algae barn 3 daya ago. There are a few on the glass.
They have attennas sticking out from the head. Flatworm or nudi? Good/bad? How to get rid of them.

 

[WickedCZ4A]

Not a flatworm if it isn't flat. Possibly nudibranch. It's hard to tell what they are from the pictures

Do you have any wrasses in your tank?
If not I'd recommend adding a wrasse and dipping your corals to see if anymore fall off

 

[Technewb]

No wrasse, but i can go get one tomorrow but qt will take awhile. What about a yellow tail damsel? Just picked up 3 for frag tanks. Could throw one in there. Definately looks a slug with attenna. Pink/red color. Seems to be on the glass next to the snails in small white shells. Hopefully they dont take over the tank.

 

[KJ]

Look like Vayssierea sp.

 

[Lovemyreef2015]

Agree ^^ Vayssierea. They eat Spirorbid & Serpulid worms. Not a bad thing unless you like tubeworms.