The Ghost of Christmas Future was one of the ghosts in The Real Ghostbusters in episode "X-Mas Marks the Spot". He did not speak at all during the episode, so the least is known about him.
He didn't speak(even though the Ghost of Christmas Past implied he could speak when Egon rescued them), but by the company he keeps one can conclude he is also a friendly ghost. Ray Stantz impersonated him when he was accidentally captured.
