The title is a double play on words. One is the typical pun between "hare" and "hair", with the bunny rendered "old and grey" for this cartoon. The title also refers to the old song, "The Old Gray Mare". Some of the lobby cards for this cartoon gave the alternate spelling, The Old Gray Hare.
Plot
The cartoon starts with Elmer Fudd sitting under a tree, crying over his failure to catch Bugs. The "voice of God" tells Elmer to keep trying to catch him. Elmer wonders how long it will it take-and is shown exactly how long by being transported "far into the future" past the years 1950, 1960, 1970, 1980, 1990, until reaching the then-distant year of A.D. 2000, after the sound ofthe gong. This offers the chance to use some contemporary gags with a futuristic twist, as Elmer finds a year 2000 newspaper. One headline says, "Smellevision Replaces Television: Carl Stalling Sez It Will Never Work!" In sporting news, another headline says, "Bing Crosby's Horse Hasn't Come In Yet!". Yet another headline, unmentioned, states, "Quintuplets Give Birth To Quintuplets". By now, both Elmer and Bugs are very old and wrinkled - Bugs even has a large white beard and a cane – and lumbago – but their chase resumes. This time, Elmer is armed with an "original Buck Rogers lightning-quick rabbit killer" gun. After a short chase, at slow speed, due to their ages, Elmer gets the upper hand, shooting Bugs with his ultra-modern weapon, with added Pinball effects and "TILT". At the moment when it seems Elmer has finally beaten his nemesis, the apparently dying Bugs thinks back to when he and Elmer were much younger. This leads to a flashback sequence with a baby Elmer hunting a baby Bugs – both are still in diapers; Bugs is drinking carrot juice from a baby bottle; Elmer is crawling and toting a pop-gun; and they interrupt their chase to briefly take a baby nap-time together. After the flashback is over, a tearful Bugs starts to dig his own grave, with Elmer getting equally emotional, but Bugs switches places with the weeping and distracted Elmer and cheerfully buries him alive instead. Elmer quips, "that pesky wabbit is out of my life forever and ever!" However, Bugs suddenly pops in and repeats the popular catchphrase of the "Richard Q. Peavey" character from The Great Gildersleeve, "Well, now, I wouldn't say that," plants a kiss on Elmer, then hands him a large firecracker, lights the fuse and quickly departs. While Elmer shivers and doesn't do anything, the screen immediately fades to black with the firecracker still hissing. The pre-written "That's all, Folks!" card appears, and the firecracker blows up in a tremendous explosion off-screen, rumbling and shaking the title card, leaving Elmer's fate unknown.
When this cartoon aired on The WB, the part where baby Elmer points his toy gun at baby Bugs' face and baby Bugs cracks his bottle of carrot juice over baby Elmer's head was cut.
See "Notes/Goofs" section below for edits done to the end gag where the cartoon ends with elderly Bugs giving elderly Elmer a stick of dynamite after burying him in his own grave and the title card shakes in response to the off-screen explosion.
