Where's Wally? is a series of children's books created by the British illustrator Martin Handford. The goal is to find a certain man, Wally, in a busy picture full of people. Wally dresses in a red and white striped shirt and bobble hat, carries a wooden walking stick, and wears glasses. In the United States the series is known as Where's Waldo? A 13-episode animated series was aired on CBS in 1991.
Season 3 - 9F04 - Treehouse of Horror III

Bart finds a Where's Waldo book in the library.

"He's not even trying anymore!"

Season 6 - 2F11 - Bart's Comet
Waldo is seen in Flanders' bomb shelter in this episode.
Season 11 - BABF02 - Hello Gutter, Hello Fadder

Homer's late for work, but has time to try finding Waldo.


"It would be so much easier if there weren't all these people in here!"

As Homer gives up, yelling "Waldo! Where are you?", he walks by in the background.

Where's Waldo information from Wikipedia.org