Around the time Mutations
came out, a very widespread rumor started going around that Beck was going to remix the Digital Underground classic "The Humpty Dance" for some rap label retrospective cd. I don't believe the cd ever actually materialized. I'm pretty sure Beck never actually made it to the point of remixing the song, so chalk this one up under "Cool Ideas That Never Came To Pass."
Beck has improvised some of the words a few times on stage (3 times in 2002, 2 times in 2013/2014).
Played live 5 times:
Earliest known live version: August 5, 2002
Latest known live version: July 20, 2014
Well, I'll be! On August 5 2002, Beck improvised "The Humpty Dance" during his concert. He rapped it while playing piano
!! Hopefully a bootleg will arise. It wasn't a full cover or anything, just a few moments of fun, but still... cool!
I haven't heard that show yet, but he did a similar thing in Dallas on August 23, but this time he rapped a bit of the song, while messing around with his toy guitar "One Man Jam."