What are these things

[ScuderiaDavis]

Can someone help me identify these things. They just started popping up.

Good? Bad? Not a big deal?

[jraker]

Pineapple sponge. Harmless filter feeder.

[ScuderiaDavis]

Pineapple sponge. Harmless filter feeder.

cool! I like when Little GOOD surprises pop up

[Squibege]

There are so many of these in my tank! Most are in the sump...

[Half Vaped]

I've got a bunch of those in my sump and overflows as well. All this time I thought they were tunicates. Learn something new everyday!