Powdery brownish black mold stuff?

Found a pile of something behind my toilet. Thought it was just a piece of garbage or something. Tried to pick it up and a bunch of brownish black powder poofed up. A closer look revealed that it also had hairs in it. If it grew that way or if it was just a big mass of stray hairs i dont know. Im really curious what this might have been. (cleaned it up since then) put some toilet paper in the toilet with this stuff on it and the water started defying gravity crawling up the sides of the toilet. Very very strange, just hoping for some answers. Thanks also if you know what this is and could let me know of its toxicity thatd be great. thanks bye.