What's this

[Toomanymatts]

Any idea what this is?  I found it in the first chamber of my 13.5 while doing a water change.  Sucked it out with a turkey baster.   I think I see two more smaller ones in there.  

[Snow_Phoenix]

Pineapple sponge. Good hitchiker and a filter-feeder. 

[Tired]

Yep. Harmless, neat. They tend to explode in population in younger tanks, if they're present, then fade back down to a more reasonable number. They like dark places and do almost nothing, except exist, multiply, and filter stuff out of the water. 

 

You've got a fat one there! Pop it back where you got it, let it do its thing.