O

O is a character who first appears in the Alphabet Attack episode "Climbing Up the Top".

"Climbing Up the Top"
O says she can roll like a wheel because of her shape, W and N are also mentioned in O's saying too, they kinda liked that saying, however, O is force to compete in a game where she and 25 other players push each other off an iceberg, causing them to die except for P and Q who make it, O later competes on the Pooping Poopers and wins.

"The Cold Wave"
O fails to build a proper snowman, thus, her team is UFE.

"Terrible Math Questions"
O gets no votes, but got cake.

"A Christmas Special"
O gets a red ball out of her present, but her team loses.

Personality
O is a girl who likes to roll on skateboards, due to her round shape, she likes to go rolling everywhere.

Trivia

 * O is the only character who has a infinite number of lines of symmetry.