richard malkin appears in two separate episodes.
when mr. eko, acting as a priest, attempts to investigate a girl who miraculously survived drowining, richard malkin tells him that he's a fake psychic. when malkin meets claire, he truly believes that she MUST keep her baby, to the point that he helps her to get on oceanic 815.
oddly enough, malkin is a "fake psychic" who is eventually able to foresee real future events (i.e. claire on the island, or whatever). similarly, mr. eko is a "fake priest" who eventually brings spirituality and "justice" to the other losties AND finds peace in his own life.