Mara Jade incoming

In the old EU, Palpatine transferred his consciousness to a clone of himself. It would start of as a younger version of Palpatine, but the darkside energy would degenerate the body so it would end up looking like ROTJ Palpatine. Eventually all the clones were destroyed and Palpatine was killed for good. He did try to transfer himself into Leia's unborn child, but he failed.