Michael Comeau, known almost exclusively by his surname, is a minor but memorable character who appears in Julie Powers' party in the first volume of the comic series. His most defining characteristic, as noted both in the story and supplementary material, is his uncanny social connectivity; he is described as someone who "knows literally everyone," a trait that extends to the reader as well with the playful addendum "including you." This quality establishes him as a key source of information within his social circle. In his first appearance, he is the one who provides Scott Pilgrim with the initial, albeit brief, piece of information about Ramona Flowers, merely stating that she is American and directing Scott to ask others for more details.

Comeau's personality is conveyed through his casual, party-going demeanor. In the comics, he is almost always depicted with a drink in his hand and his mouth open, suggesting a perpetually gregarious and talkative nature. His dialogue often contains bizarre and unexplained claims, the most notable being that he possesses a ring that he says he obtained from the future. Given the fantastical logic of the Scott Pilgrim universe, where vegans have telekinetic powers and people can travel through subspace, such a claim is presented as being potentially truthful. This adds a layer of quirky mystery to his character, suggesting he might be more than just a typical partygoer.

His role in the story is primarily functional, serving as a connector between characters and a dispenser of minor plot information. However, he also contributes to the metafictional humor of the franchise. In the film adaptation, he appears at the Chaos Theatre delivering a line improvised by the actor, commenting that he hears "the comic books are better than the movie," a winking nod to the source material. His key relationships are with the wider cast of friends and acquaintances in Toronto, including Scott, Wallace Wells, and Kim Pine, but he is not part of the core friend group. He is based on a real-life Toronto artist and friend of the series' creator, Bryan Lee O'Malley, who has described the nature of the character's origin as "complicated".

While Comeau does not undergo significant character development, his presence is consistent across different adaptations. He appears as a cameo in the anime series Scott Pilgrim Takes Off, attending a musical performance in the final episode. Regarding his abilities, aside from his seemingly supernatural social network, a bonus comic strip titled "The Uncanny Comeau" depicts him as having a brief, bizarre talent for combat. In this story, he opens a restaurant and fight club, using cheap knock-off Starmen from the Mario video game series that can play songs on command. He uses one to play "This Charming Man" by The Smiths while fighting Scott, gaining an advantage until Scott distracts him by asking about a tattoo. Despite this display, he is ultimately defeated. This strip, along with his claims of time travel and a future ring, hints at a potential for abilities far beyond those of an ordinary background character, though these aspects are rarely explored in the main narrative. He is also one of a handful of characters in the series to be associated with time travel.