|“||I've buried things that ain't no one's ever seen again.||”|
|— Colin in Birthday Forever|
Colin is an inhabitant of Endless Island and is a recurring character in Twelve Forever.
Colin has a very bloated, lumpy gray-colored body, thick legs, and very slim arms. He has a long nose and a red mouth with only two upper teeth visible. His usual posture is hunched over.
In his powered up form as seen in Together Forever, he stands upright and has a very toned and muscled physique, and has a large bulbous tail covered in rounded spikes.
Colin is neurotic and very nervous. He is also not very smart, as shown when he repeatedly tried to force a square peg into a round hole in Spring Break Forever. Colin enjoys drawing and making paintings of himself, as well as tending to his indoor flower gardens. He will eat nearly anything, including paper towels, pencils, and even other islanders like the deer snake. It's hinted that he has a darker side that he keeps secret from everyone else, like when he suggested that Twelve and Todd should bury things in the island In the episode "Birthday Forever".