Urban Dictionary has a wonderfulexample of what I’m talking about, but I’m very curious to know the story behind it. I’ve got some vague notion about early film or something, but I might be thinking of something else. Anyone know? I’m quite certain it predates Anchorman…
What you may be thinking of is the classic radio program Fibber McGee and Molly. It’s best known tagline was T’aint funny, McGee! (Something my parents used to say when I got into mischief as a child.
What relation if any that this might have to the expressions you link to I don’t know.
“Fibber McGee” has always suggested someone who lied a lot to me, though I’m too young to know the show. So the derivation could take that as a starting point for a back-formation:
fibber + McGee ==> “lots of lies” + McGee ==> lots of x + McGee
I had not heard the “McGee” suffix to mean this, but I really like it, so I will make a point to work it into some conversations.
“Oh Fatty McGee, you’re the fattest!”
From the track “Fatty McGee” on the album “They’re all Gonna Laugh at You!” by Adam Sandler.
Released: 1993
(Just to definitively demonstrate that the usage predates Anchorman. Also I used to listen to this album in junior high and hadn’t thought about it in a long time 
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