A second opinion (and the prevailing one, it seems) is that Charvonah is Eliyahu HaNavi...The idea being that Eliyahu did not actually die, but rather ascended in a fiery chariot (as described in the Bible).[Kings 2:2:11] Consequently Eliyahu moves freely through the planes of reality, enclothing himself in whatever is the appropriate “substance” of each world. [TB Eruvin 43b]