I've been planning a written form of Monty Python's Spamalot, then remade in comic form when I've written the script.

The Cast:
The Court of Camelot:
Gordon as King Arthur
Murdoch as Sir Lancelot the Homicidally Brave
Stan Marsh as Sir Robin, the Not-Quite-So-Brave-as-Sir-Lancelot
Me as Sir Dennis Galahad, The Dashingly Handsome
Homeschool Winner as Sir Bedevere, The Strangely Flatulent
James R. as Patsy
Kyle Broflovski as Concorde
Strong Sad as Brother Maynard
Kenny McCormick as Sir Bors
Homsar as Sir Not-Appearing-In-This-Show

Other characters
Danni as The Lady of the Lake
Joey as Not-Dead Fred
Homestar Runner as Robin's Lead Minstrel
Jacob as The King of Swamp Castle (aka Herbert's Father)
James as Prince Herbert
Eric Cartman as French Taunter
Diesel as The Black Knight
Strong Bad as The Head Knight who says "Ni!"
Douglas as Tim the Enchanter
My mom as Mrs. Galahad
The Cheat as The Killer Rabbit of Caerbannog
Bill as Hiccuping Swamp Castle Guard
Ben as Swamp Castle Guard who doesn't hiccup but has trouble understanding simple concepts
William and Dustin as Sentries
Thomas as the Historian
Sir Topham Hatt as The Mayor of Finland
Emily, Molly, Wendy Testaburger, Bebe Stevens, Chelsea and Blake as The Laker Girls
Random characters as Knights of the Round Table
Pom-Pom, Coach Z and Bubs as Robin’s Minstrels
John Cleese as God
(insert random character) as Holder of the Holy Grail