I've had planted tanks before and decided about 6 months ago to start a 29 gal planted tank again. I have some Bolivian Rams, Neon Tetras and Green Cory's, as well as an Albino Bristlenose and a few Red Cherry Sakura shrimp. Anyways, I was doing a water change and pulled out a piece of my driftwood with attached plants and this dude came out of it. Looks like a really large slug almost. What the heck is it and how did it get in my tank? Should I leave it in there or remove it? I've never seen this in any of my other planted tanks before.