I have a couple things I've come across while trying to ID a hitch hiking crab and I'm not sure what they are.
This one was pretty grippy to the tub.
The shape kind of looks like a mantis shrimp but not sure. It's pretty small.
I have some helpful bristle worms but this one was different.
Pretty sure this is an aiptasia but it hasn't moved (except to shrink into the rock to hide sometimes) and the peppermint shrimp hasn't eaten it. Not sure if the peppermint shrimp hasn't because it has been hiding on the other side of the tank or it's not an aiptasia.
Looks like some kind of shrimpy thing but not sure.
I think the red stuff is some sort of sponge but not sure about the green. The rock was tan when I put it in.
I also have some oval white flat things that only show up at night on the tank glass and eat the algae. They're pretty small, maybe a millimeter or so, and I've been able to narrow down they are not any of the common flatworms which are "bad." Going to try again tonight to get some decent photos.