This is a Crassula ovata, 'Gollum,' maybe a Skinny Fingers type...The brown on the stem is natural aging. It looks like a healthy specimen to me. Best to keep these in bright light, with a fast draining potting medium.

Christopher

I have one, too :)

You can take cutting of the branches and they root within a month or two. Pretty hardy plants.

The smaller cuttings can get sunburned though, so be careful.

I have a neighbor in my neighborhood where this plant (or a similar variety) became a pretty sizable tree.