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8.
When someone eats cereal for breakfast, lunch, and dinner.
Person 1: Dude buy yourself a sandwich your becoming a cereal killer

Person 2: SHUTTUP IM BEAUTIFUL *MUNCH MUNCH MUNCH*
by triple anal rape January 16, 2014
7 2
 
9.
A person who takes an inappropriate amount of milk from the carton for his own satisfactory, leaving a very small ounce of milk inside the carton, not thinking of the others who live in the household.

By doing so, the next person who has a desire for cereal, pours the leftover milk into his cereal bowl, leaving an uneven bowl of milk and cereal.

It is basically the person, or cereal killer, leaves a small amount of milk, and someone else attempts to eat cereal, but is instead left with little milk and a lot of cereal, blaming the suspect.
Steve: Hey, you alright? Did you eat any breakfast?

Jake: No, man, it was because of that cereal killer,

Craig.

Steve: Don't worry, dude, you're not alone. You're not the only person who lives with a cereal killer. I live with one, too.
by ProcrastinatingPanda June 14, 2011
7 3
 
10.
A person who mindlessly kills (or eats very rapidly) bowls of cereal multiple times day (Someone who usually carries a spoon with them everywhere).
The next victim of the Cereal Killer is that Cinnamon Toast Crunch.
by BobbyBirdman September 29, 2010
6 2
 
11.
When the milk you pour on your cereal turns out to be sour and you have to dump the cereal out.
Cereal Killer. When the milk you pour on your cereal turns out to be sour and you have to dump the cereal out.
by The Irish Lad July 28, 2010
9 7
 
12.
One whom takes pride in or makes thier life revolve around CEREAL. Breakfast of champions! Nothing starts your day off right better than a bowl of peanut butter captain crunch.
I wake up and start my cereal killer routine( watch reruns of adult swim or transformers most the day eating cereal).
by mjReal December 24, 2006
9 7
 
13.
as in fruit loops. one who knows stuff. crazy hax0r.
by Anonymous February 09, 2003
5 27