Diane Ladd - weirdest Oscar nominated performance ever?

I can't think of a more offbeat acting nomination at the Oscars than Diane Ladd's scenery-chewing bad momma in David Lynch's weird (and to me mostly tiresome) Wild at Heart. A truly bizarre choice, a far cry from anything one would expect to see turn up at the Academy Awards.

The only other contender who comes to mind is Ann-Margaret, who writhes on the floor as basked beans rain down on her in Ken Russell's Tommy.

I guess the 'non-human' nominees are worth noting -- Cecil Kellaway as a Leprechaun in The Luck of the Irish, Jeff Bridges as an alien in Starman, Ian McKellen as Gandalf in The Fellowship of the Ring... not sure if I missed any there.

Can anyone suggest any unusual nominated performances that I have not mentioned?