Need a ID on this thing

[Josh jones]

so my tank has been up for like 5 months and I noticed these things growing on my heater. Can some one tell me what they are and are they ok to be in here thanks a bunch

 

[143MPCo]

Pineapple Sponge, filter feed.

 

[Baby Ray]

Pineapple Sponge, filter feed.

+1

 

[tcarter1936]

+1 pineapple and angels love them