Help ID please

[smokin'reefer]

I've got some new mystery growths in my biocube. This guy looks cool. Closest thing I could see on lionfish's guide was maybe some kind of sponge.

Any help would be greatly appreciated.

 

[KJ]

Sponge

 

[smokin'reefer]

Thanks. I did my homework first at lionfish but wasn't 100% sure.