what is a coral cactus?

the pink coral cactus is a grafted plant from the cactus family, but is actually an african succulent that has evolved to look like a cactus.  it is a variegated eurphorbia lactea crest (you could tell, right?) that is grafted on some sort of cylindrical euphorbia stock (don't you have a couple of those?).  mixed in is a sharp agave  and prinkly pear cactus (my hands have battle scars), donkey tails and native shells.  this lynzarium measures 15 inches high with 9 inch diameter, a big boy.  available at hudson, boston.