Identification- is this an algae ?only located on 2 rocks stays short and grows like it’s a polyp or patches

[gobie1313]

 

[BiGGiePauls33]

Probably some type of sponge.

 

[ChrisV]

+1 for sponge

 

[gobie1313]

+1 for sponge

So it’s a good thing
Thanks all