This is an agave (I think) that I bought from a greenhouse this past summer. I will post some close up photos as well for ID help. It is in a 4" pot. The brown fuzz at its base is the remains of a fern that was growing with it when I got it. I knew that couldn't be good. Anytime you see a fern and a succulent growing in the same pot, one of them must be really mad. In this case, it was the agave (until the very second it left the building with me, and the fern's one frond crisped and died, which I expected would happen). I removed all the rotted leaves and it's recovering quite well, but probably would do even better in a looser mix.