What is this in my sump?

[jlmiller1057]

I think it is a sponge but I've never seen it before. Is it good or bad? I mean it doesn't seem like it has effected anything negatively but I'm pretty curious. Thanks!

Not quite sure why the pictures uploaded upside down? lol sorry

 

[cloak]

Harmless sponge IMO.

 

[Betta132]

It's just one of the various weird sprawl-y sponges. Harmless.