Algae or Sponge ID?

[fishski13]

I recently found this web looking thing in my tank. Not sure if it is algae or a sponge or something else. If anyone knows what it is and has any info that would be nice. Thanks

 

[Eatfrenchfries]

Looks to be the beginning of a type of sponge. Nice.

 

[Zach B]

+1 for sponge