Squid Doodle is a picture drawn by Patrick in the Season 2 episode Frankendoodle.
The Squid Doodle
When Patrick drew the doodle on the ground, SpongeBob thought it was another Jellyfish, as he drew one earlier, but Patrick said it was Squidward.
Patrick: Hey, another Jellyfish!
SpongeBob: It's Squidward, silly!
It soon came to life, shaking its fist and yelling gibberish. It is soon erased by Patrick because they couldn't allow it to roam around town, prompting Patrick say "Poor Squidward".
Trivia
Doodle Squidward is a bonus boss in Drawn to Life: SpongeBob SquarePants Edition