Bud Luckey received an Academy Award nomination for Best Animated Short Film in 2004 for the Pixar short Boundin’ about a dancing sheep, where Luckey also provided the voice of the narrator.
Luckey provided a number of additional voices to both Disney and Pixar over the years.
He was the voice of Eeyore in Disney’s 2011 Winnie the Pooh movie and he was the original voice of Rick Dicker in The Incredibles.
That performance is being taken over by Jonathan Banks in Incredibles 2, it’s unclear if Luckey’s illness was the reason the recasting needed to be done, though Luckey is currently credited as having done some voice work for Chuckles the Clown in next year’s Toy Story 4.