K
From the Un-Mario Wiki, the Mario no-ledge-base.
“K, I get it.”
—Toad, K
The letter K first appeared in the title of Donkey and Pong, where it appeared in an early childhood stage. It first appeared as an adult in the title Mario Kart. The letter K has since gone on to be a vital character in the Mario series. K is also the member of the ABCDEFGHIJKLMNOPQRSTUVWXYZ group.

