The Premise: Cowabunga. Word with a weird origin (that being Chief Thunderthud on The Howdy Doody Show, long, LONG ago). So I guess I decided to see if I could take that origin and tie it into a fun one page script.
The alternative to this was to make a horror comic. Prove I made the wrong choice.
We open on the turtles, all sat around a table, eating pizza and relaxing. All eyes are on Michelangelo, who is looking back at them with a mouth overflowing with cheesy goodness.
Leonardo: So, Mikey... Where *does* your catchphrase come from anyway?
Raphael: That stupid 'Cowabunga' thing you won't quit yelling.
Close-up on Michelangelo as he swallows his mess of pizza.
Michelangelo: MMM! ->gulp<-
The other turtles all do spit-takes as Michelangelo explains his catchphrase to them.
Michelangelo: I got that from my sensei!
SFX (spit-take): SPWOOOOSHHH
A dim flashback panel, with Michelangelo kneeling before the shadowy form of Chief Thunderthud. Note: All captions, to better frame who each person is, have the face of the speaker at the edge of each box.
Leonardo(caption): Master Splinter?
Michelangelo(caption): Naw dude, my OTHER sensei. I went to him alone, whenever you guys just thought I was slacking off.
Donnatello(caption): So you WEREN'T just sneaking off for more pizza?
Raphael(caption): Just tell us who your sensei is, already!
We view this flashback from the other side, with Michelangelo kneeling in front of a large, muscular version of Chief Thunderthud, a tomahawk in each hand, and a large luxuriant moustache.
Michelangelo(caption): Don't have a cow, Raph.
Michelangelo: Howdy, dude- I mean... Sensei.
Chief Thunderthud: Cowabunga, Turtle-Face. Shall we begin?
Michelangelo(caption): He was CHIEF THUNDERTHUD, the only Indian to have a moustache, and he taught me EVERYTHING.