
From California to the New York island,
I'm a real Yankee Doodle boy.
The Big Bang Theory Season 4, Episode 7

Excuse me, Penny,
but "Doodle Jump" is a game.
The Big Bang Theory Season 4, Episode 19

that's just a DOODLE of
a hyperelliptic Riemann surface.
The Big Bang Theory Season 7, Episode 20