"We will soon have our ticket to CPI. We're one step closer to escaping this hell."
-Gary congratulating himself and his assistant as they make their preparations to escape the island and get to CPI
Gary is an iconic mascot from Club Penguin who makes a one-time appearance in Club Penguin Shutdown as a tragic protagonist.
Background
Biography
Gary's first and last appearance was in the holiday special Halloween 2. He and his lab assistant, Jerry, had recently finished a reverse teleportation machine that could bring penguins from other places to his lab. Gary had intended to use it to bring a penguin from Club Penguin Island (CPI) to his lab so he could ask for directions to the new island, but when Gary tried to launch the extraction, the machine had an unexpected side effect: the radiation inside the machine caused the extracted penguin to come out featherless and horribly deformed, making him the first Mutant Penguin, Sludge.
Confused, angry, and in pain, Sludge began running around the lab while yelling at Gary to fix him. Gary tried to calm the mutant down, but to no avail; he kept running and accidentally reactivated the machine after bumping into the controls. Jerry tried to help as well, but the Mutant Penguin knocked him into the machine's terminal, causing Jerry to get mutated too. The machine extracted another penguin named Daisy and fused her together with Jerry, turning them into Double, the two-headed Mutant Penguin. Gary tried again to calm Sludge down but still got no result; he charged at Gary but tripped and slammed into the control panel, sending the machine into a frenzy. Sludge started banging the machine in a fit of blind rage. Gary, now frustrated, tried to restrain the furious freak as his machine generated a third Mutant Penguin before breaking down. Gary pleaded with Sludge and promised to fix him, but Double commented that the machine was broken and they were stuck as mutants forever, and that got Sludge mad again. He grabbed Gary by the head and squeezed. Gary pleaded again, desperately offering to fix the machine, but Sludge kept squeezing, until Gary's brain popped out of his head and he died.
Sludge squeezing Gary's head
At the very end of the episode, Gary's corpse was seen lying where he'd fallen when he died, his body already starting to decompose. Then, one of the Hybrid Sea Monster's arms broke into the lab from underground, observed Gary's dead body, and dragged it down. It then reemerged and grabbed Gary's brain. Moments later, the Monster suddenly spoke its first words: "MMMMM, THAT WAS SCRUMPTIOUS..." This may imply that the Monster might've absorbed Gary's intelligence after eating his brain.
Personality
Unlike most of the other Mascots, Gary's personality hasn't changed much since the Shutdown. He's a bumbling but brilliant scientist who's usually pretty chipper. Even though he tried to leave the old Club Penguin and escape to Club Penguin Island, he shows a great deal of concern for other penguins as he felt really bad after accidentally mutating the light blue penguin with his machine and tried to help him, but this was in vain as the mutant was too angry to be reasoned with.
Relationships
Mutant Penguins
Gary accidentally created Sludge with his teleportation experiment gone wrong. Sludge hates him for this and killed him, even though Gary offered to help cure him.
Double was once Gary's loyal lab assistant Jerry during the Shutdown. He likely misses him. The other half, Daisy, has no relationship with Gary.
Shell has no relationship with Gary, as he had only been created moments before Gary was killed by his "brother."