The go-to excuse for being unable to do something. Sounds suspiciously like a mild medical condition. Originally a quote from the first episode of Clone High, "Escape to Beer Mountain: A Rope of Sand," spoken by George Washington Carver's anthropomorphic peanut.
Hi'o, Guvna's. I'd shake your hands, but, you know, peanut arms.
I'd do the dishes, but... peanut arms.
I'd give you some of my fries, but y'know... peanut arms.