A Japanese detective who plays in the anime "Deathnote".
He eats lots of food with sugar in it, like cake. By now he probably has diabetes of all the sugar he ate, also he didn't die out of a heart attack it was diabetes.
Kira: I CURSE YOU, L! WITH YOU I CANNOT BECOME THE GOD OF THIS WORLD!
L: Have some cake.
L is a modern internet term and the oppisite of W. L is a shortening of "lose".