Michael Keaton did not receive an Oscar nomination for portraying Betelgeuse in Beetlejuice.
Eventually the couple seeks help with the actual titular character, a "human buster" who specializes in getting rid of human infestations for ghosts. A character we only briefly see in the first act from behind seeing a new opportunity in the Maitlands as some sort of opportunity for himself. He appears more clearly as he performs a tv cowboy ad for the Maitlands selling his services like a bad used car salesman with phony energy right down to his western accent. He appears partially one more time to lure than eat fly as we get more of the craggy voice Keaton uses before he goes about devouring the protesting fly. He eventually appears past the halfway point when the Maitland's finally decide to potentially use him to scare out the new humans.
And we have Keaton's full entrance, which has become such an iconic character for him that it is easy enough to forget he was mostly slightly off-beat lead before this performance, which is a complete transformation for him, not just for the rather extensive makeup. Keaton's performance is one all about energy as he just goes at the part of Betelgeuse full force for his technically brief screen time as the titular character, and goes all in. All in as a disgusting lout, where Keaton's whole manner is about as idiosyncratic as they come. From that voice again as a dead man, guttural to whatever comes out, though personally I think his funniest moments are when he shifts that up, and his physicality of the performance. There isn't a part of Keaton's body that he kind of just let's be, in the manner of which he stands with his gut forward, the way he saunters around as though to always be some kind of surprise, to particularly the way he cocks his neck around, with a kind of snake like demeanor even when he's not turning literally into a snake. His delivery to go along with this is rapid fire, in going from idiotic, to weirdly insightful, to accommodating, to crass, to complete perversion all in a matter of a few seconds as Keaton just plays around with the part fitting for a supernatural man whose had nothing but time to indulge himself, and seemingly make use of any mischief he can that amuses himself. Keaton's performance is just the ball of energy to what the film orbits, despite again not really being in the film all that much, but it doesn't matter because he is indeed captivating every second he's on, to the point he just infects everything with the Betelgeuse name because he is indeed so memorable. And part of this is of course just being funny by "taking the piss", for the lack of a better phrase, out of everyone and everything he sees. A favorite of mine being his rundown of his qualifications where Keaton goes to his most normal Keatonness if more refined, as he starts as a proper Juilliard actor, before quickly falling apart to every bit of viciousness of state in the black plague and just loving laughing at The Exorcist.
But even in that bit of comedy, which completely works as such, what Keaton also manages to do is create both an unpredictability in his performance and an unpredictability in the character. Although I wouldn't call it a full tone shift exactly, what Keaton is able to do is dance a bit in the darkness along with comedy to provide some sense of danger to the character even as he's more than a bit of a goofball. This is best represented when he is tasted by the Deetz's daughter Lydia (Winona Ryder) to save the Maitland's who are being exorcised, on the condition that she marries him in order for him to escape his current existence. All starting with the iconic line from the film "It's showtime", with such a perfect fiendish glee, along with his little dust off gesture before holding his arms as the ideal "I'm ready". And this is the showcase for Keaton who just is on throughout the sequence, from his fully creepy opening circus bit where he disposes of two of the guests, to the following purely hilarious voice change when noting "He won't do two shows a night", until being a different kind of creepy as he welcomes the Deetz's as his family before proceeding with the wedding. Something where again Keaton just is in this particular flow that is just so wonderfully specific in the amount of momentum he brings in every physical move, every vocal reaction to just everything, with particular highlights being his pondering his marriage before his casual yep, to his hilarious squeal when someone successfully says his name, to his callous yet sincere dismissing of his wife, whose ring...and finger he has. Keaton's great because he is the villain, he is the comic relief, he's even the hero all in the same scene. And as much as his screentime is limited, he does steal the show in with the character, which evidently he largely ad-libbed much of, and apparently even gave input into the specifics of his look. None of which is surprising given Keaton just is this role, in a way few actors are a role, where they instantly became a cinematic icon...which is no small feat.
