Check out Austrocylindropuntia vestita monstrose, it could but that, but I do not think so. What it looks like most to me is a monstrose version of regular Opuntia, but it is not quite clear afaik which Opuntia that is. I am trying to remember the site where I saw a thread that talked about this plant. They gave it a different name and when I googled that I came across a picture of a plant that looked like the plant in your picture with a branch that had reverted to its normal Opuntia appearance...
I was given a pad of this plant by a fellow cactus enthusiast so it is in my plant staging area trying to become rooted. He also did not know what the original Opuntia was it derives from.
