Starfish hitchhiker ID please?

[ToadstoolCoral155]

Found ONE of these in my tank today. He appears to have spikes, is a dark red/brown, has one arm that is white 4-5 arms, and crawled around my corals.
I could use detailed information on how to care for him assuming he isn't bad for my tank

 

[Crabs McJones]

Possibly a brittle starfish. Awesome hitchhiker if it is

 

[ToadstoolCoral155]

Possibly a brittle starfish. Awesome hitchhiker if it is

I thought they had 5 legs instead of four. Also how do I care for it? (Also he may have 5, I just don't think i've seen it, he's really small)

 

[WV Reefer]

I thought they had 5 legs instead of four. Also how do I care for it? (Also he may have 5, I just don't think i've seen it, he's really small)

Sometimes they can have no legs! You don’t have to do anything..... just let him live his life.

 

[Crabs McJones]

I thought they had 5 legs instead of four. Also how do I care for it? (Also he may have 5, I just don't think i've seen it, he's really small)

They're scavengers, good part of your cleanup crew. They'll eat whatever is left over

 

[kirstyflash]

Mine have 6 unless the coral banded shrimp or scooter Blenny find them....then they have them nibbled off