Found in South Africa, Namibia and Lesotho, Crassula muscosa is a thin branched succulent with tiny stacked leaves up to a foot tall. It is called "Watch Chain" for it's similarity to a segmented watch chain or band. It's a fast grower and appreciates light shade and regular water. It gets tiny greenish white flowers. I think there may be a couple varieties, I can't be sure. The one on the right below seems to have a more upright habit and thinner stems.

Closeup of stems

Another variety?