think it's algae, but what kind?

this is on the shroom rock from lil' bro's tank that's now in my tank

 

Its a little hard to see, at least for me. Luna

 

first pic is the best, maximize it, on the right, above the calurpa, reddish brown

 

Never seen it before, at least that small/young. Luna

 

anyone else? i need to know if i should take it out and scrub it off before bed, last thing i want is an algae infestation.

 

I don't think is bad, but don't take my word for it, never seen it before

 

do you see what i'm talking about though? the reddish brown, kinda stringy w/ lil' balls on the end.

 

Tangster, lil' help plz.

 

yeah! I see it very well, still don't know. but on the second pic there is 2 snails doing the humteehump....lol

 

Those are Hydroids, you might wanna torch that rock ASAP before they spread.

Ive had those before, and thats the kind that stung me when they became a jellyfish.