ID help on a few hitchhikers

[brendann993]

Hey guys, after some help on a ID'ing/confirming IDs on a few hitchhikers I've found after lights off and browsing the tank.
Thanks in advance
First one im pretty sure is a Limpet.

Second I think maybe a bristle cage worm

Third I'm not sure about. I'm thinking the worse and aiptasia

 

[Goaway]

The last photo is just a type of feather duster. Keep an eye on the limpet. Most are just algae grazers. Everyone is pretty safe of a hitch hiker.