Yellow Sponge ID

[SAWFISH]

I was moving some rock around in my tank today and noticed these yellow objects on the rock. I am assuming they are some kind of sponge and are harmless but wondered if anyone could give a more confident/specific name on what these critters are.

 

[EeyoreIsMySpiritAnimal]

Definitely sponges, harmless, I named mine Larry…

 

[albano]

Definitely sponges, harmless, I named mine Larry…

Reminded you of old boyfriend?

 

[Hyde2406]

I have it all over even climbing the back wall. Never been a problem for me but was warned If it dies it releases a toxin. I had a heater malfunction recently (over 90 degrees) and still didn't have a problem.