This short is one of several pre-August 1948 WB cartoon shorts that lapsed into the public domain due to United Artists failing to renew the copyright in time.
The title of the short is a reference to the 1942 Warner Brothers film version of the 1939 George S. Kaufman Broadway comedy The Man Who Came to Dinner, in which an overbearing house-guest threatens to take over the lives of a small-town family.
While out on the hunt for rabbits, Elmer receives a telegram from "Eastern Union" saying his Uncle Louie will leave him $3 million in his will, as long as he doesn't harm any animals—especially rabbits. "We're in the Money" plays in the underscore. Elmer, with his rounded-L's-and-R's speech impediment, of course cannot pronounce "Uncle Louie" correctly; which sounds more like "Uncoh Wooie".
Bugs, with characteristic élan, takes full advantage of the situation by moving in with Elmer.
As he showers and shaves, Bugs sings "Angel in Disguise", from the 1940 Warner Brothers film It All Came True (which, like The Man Who Came to Dinner, starred Ann Sheridan).
Elmer tries to coax Bugs into leaving, gently patting him on the head, which Bugs claims is terribly hurting him. Bugs references a running gag from the radio show Fibber McGee and Molly when he threatens to call Uncle Louie: "Operator, give me Walnut three three fifty… Ohhh, that you, Myrt? How's every little thing?" (Arthur Q. Bryan, the voice of Elmer Fudd, also played "Doc Gamble" on the Fibber McGee show.)
After fulfilling the stipulations of the will, and suffering all manner of hijinks from Bugs, Elmer gets a special delivery letter from his uncle's lawyers showing that, after taxes and fees, he has no money left to spend and keep for himself; in fact, he owes them $1.98 on the $3 million inheritance ("pwease wemit"). Realizing that even if he fulfills the will's conditions he will not receive any spending money anyway, Elmer is then free to vent his anger on Bugs, and a chase ensues. Bugs escapes, but Elmer is given a large, garish Easter egg containing several tiny Bugses who simultaneously ask 'Eh, what's up Doc?' and start leaping around the house.