This looks like a prickly pear cactus, or Opuntia. Looking it up, it seems there are quite a few different types, and I have no idea of the exact species in your picture. Also it's hard to tell from the photo whether those yellow prickly pears are on their way to turning red like most ripe prickly pears (or "tunas" as they are also called), or if they are going to stay yellow when ripe.
Most prickly pear fruits are (supposedly) edible, as are the leaves (the pads, or Spanish "nopales"), but the spines and the irritating little hairs that accompany them are extremely treacherous if you don't know what you are doing. So be super-careful if you choose to go near one of these plants.