Squirrel

The Squirrel appears numerous times in the series.

Opening Sequence
At the beginning of the song, a camera pushes a squirrel out of a hole in a tree. Soon after, squirrels are seen peacefully sitting by DJ. This continues until a fish falls on him, causing the squirrel and all of the other animals to attack him, even though he is supposed to be an animal lover.

The Sucky Outdoors
The squirrels make fun of Katie and Sadie when they get lost in the woods by mimicking their argument by mouthing the words and making the faces.

X-Treme Torture
Early in the morning, an annoyed squirrel smacks a tweeting bird off a tree.

Search and Do Not Destroy
A squirrel is seen coming out of the tree with a cup of coffee.

Camp Castaways
A squirrel is seen floating away from the island, on top of a submarine.

I Triple Dog Dare You!
A squirrel in the forest turns dramatically towards the camera after hearing Heather scream, in a parody of the famous "Dramatic Chipmunk."

Total Drama Action
Like almost everyone in the show, the squirrel seems to have a crush on Justin, as it has fainted due to his "powers" in some episodes.

Dial M for Merger
The squirrel falls into the tomato bath in which the cast is sitting in after smelling their stench.

Aftermath: Bridgette Over Troubled Water
The squirrel makes a brief appearance in the aftermath in a never-before-seen clip of Harold's "best" moments. The squirrel is seen punching Harold in the face, with it's fist enlarging to a much greater size, after it becomes annoyed with his stream of trivial facts.

Aftermath: Revenge of the Telethon
The squirrel is seen during the "DJ's World of Animals" segment, in which a clip is shown of DJ feeding a squirrel food in Central Park, when a bicycle suddenly runs over the squirrel, squishing it to the ground.

Awwwwww, Drumheller
Two squirrels were among all of the animals (and Ezekiel) seen evacuating from the Total Drama Jumbo Jet moments before Sierra accidentally blew it up.

Trivia

 * The squirrels, a dolphin, the eagles, the chipmunks, and the sharks are the only animals that have been blown away by Justin's charm.