Small sea stars Good or Bad?

[moespeaking]

Ive had my pico 2.5 bow for a week and am noticing 2-3 small white sea stars. I thought somebody told me these guys were bad once but am not possitive. Their points arent as defined as a other sea stars ive seen and dont seem as symetrical. maybe a nudibranch of some kind? Cant find much online about em cause I dont really know what to call them. I have no camera so cant post a pic. any input should help me out.

 

[moespeaking]

Just got a good look at it, it has 3 big arms and 3 small arms pretty sure it is a star of some kind.

 

[Paliya]

Asterina starfish?

Generally considered good guys

 

[moespeaking]

i'd say that looks exactly like them, thanks Paliya