Can you help a new guy out?

[Brainthestrong]

Been in hobby for a few months now and its been rough. Had two ich outbursts, aptasia, a rogue emerald crab and now these guys. May you please help me ID them. I just want to make sure they aren't aefw. They look closer to aphiscolops.

 

[Joeganja]

Yup. Flatworm. You should probably dip any rock or coral you add into your tank. The number one rule to keeping outbreaks of disease and nuisance bugs is to do whatever you can in the beginning to prevent them. Quarantine fish, dip corals and rock.