i'm cereal

Meaning I´m serous. From SouthPark episode.
Always used in a humoristic way.

Nobody is gonna believe you didn't eat the cookies.
But i'm telling you it wasn't me. I'm cereal!

For sure dawg, I'm cereal!

Newbie, whightey, or old person trying to say "Fa`sh0w, I'm serious!"

n00b1: `/0 |)06 !/\/\ 50 1337
God: Really?
n00b1: For sure dawg, I'm cereal!