Danny faces threats of many kinds, including vengeful ghost hunter Valerie Gray (Cree Summer) who, for a short period of time, becomes his love interest, an enemy half-ghost Vlad Masters (Martin Mull), an old college friend of his father's and considered to be Danny's true arch-rival, and even his own parents who, as ghost hunters, view Danny Phantom (as they would and do to any ghosts) as a menace to society.