Eddy's Brother is the unnamed older brother of Eddy, who had moved out of his parents' house sometime prior to the show's current setting. Until Ed, Edd n Eddy's Big Picture Show, Eddy's brother was never seen, only mentioned by Eddy and the other characters. He made his debut in the movie as the true main antagonist, and is the only adult character to be seen and heard on the show. His actual name remains unknown.
Eddy's brother is at least a head taller than Eddy and wears a dirty brown newsboy cap, yellow sports jersey with the number "62" on it, red flannel jacket, khaki pants with a wallet chain similar to Eddy's pants, and greenish-grey shoes. His face and hair is somewhat similar to Eddy's, though he has a much more pronounced chin and goatee.
Because Eddy's Brother never appeared on the show until the very end, the only information about him could be gleaned from the other characters' talking about him, mainly Eddy. According to Eddy, his older brother was extremely multi-talented, being a "whiz" at everything from brick-laying to bouzouki playing, to chewing ice cubes to setting up traps. He was also a master prankster: in season one's "Fool on the Ed," the Eds create the El Mongo Stink Bomb, which Eddy claims is a recipe from his brother before he moved out. For the most part, Eddy speaks very highly of his brother, considering him his role model and wanting to be as cool, smart, and respected as he claims his brother to have been. It's later revealed in "Ed in a Halfshell," where Eddy sets himself the task of making Jimmy his protégé, that we learn that Eddy's treatment of Jimmy is similar to that of his own brother when they were younger, giving a small glimpse into their relationship.
The third season offers more details about Eddy's brother, including a trip into his bedroom in "O-Ed Eleven", which had previously been walled off for unknown reasons. Eddy's brother's room contains a multitude of bizarre items, from a stuffed camel wearing a fez, to a bed that folds up into a refrigerator, to an entire car with a trunk full of random garbage and a live snake (which Eddy claims he'll inherit someday).
In "An Ed is Born", Eddy receives a "care package" from his brother labeled "To Pipsqueak" (his "affectionate" nickname for Eddy). It's revealed to be full of baby items, including a diaper, a pacifier, and a toy rattle, hinting that Eddy's brother does not think highly of his younger sibling.
The episode "Ed... Pass it On..." , where Eddy spreads a rumor that his brother is coming back home, reveals further glimpses into Eddy's brother's relationship with the rest of the Cul-De-Sac kids: Kevin becomes a groveling, nervous wreck, Nazz swoons at the thought of Eddy's brother, and Rolf builds an entire wall and moat around his house for fear that Eddy's brother will steal and/or harm his chickens. Sarah and Jimmy are unphased- either because they honestly don't care about Eddy's brother, or can see through Eddy's lie.
In Ed, Edd n Eddy's Big Picture Show, the Eds go on a journey to find Eddy's brother so they could live with him and hide from the other kids (whom they had severely injured in their latest scam). At first Eddy's brother offers to help them out, but quickly shows his true colors when he starts playing sadistic games with Eddy, first twisting his foot around while Eddy pleas "uncle", and then throwing Eddy against the door of his trailer over and over like a basketball. The other kids manage to stop Eddy's brother from further tormenting Eddy, which resulted in Eddy's brother getting hit in the face with a door and getting knocked out. He is last seen being dragged back into his trailer by The Kanker Sisters, who presumably torment him further.
In the end, Eddy tearfully admits to Double-D that everything he said about his brother was a lie he had made up to sound "cool" so that people would like him. In reality, his brother was a cruel, sadistic bully who abused Eddy all his life both verbally and physically. This plus Eddy's paradoxical admiration of his older brother would explain his own abusive behavior and inflated, fragile sense of self-worth and need for attention. Fortunately for Eddy, Double-D and the other kids forgive Eddy and the Eds, and they leave the park together as friends.
- It was shown in "O-Ed Eleven" that he has had 13 dates.
- He is the only real adult to ever fully appear in the show.
- When Sarah and Jimmy impersonated Eddy's Brother in "Ed... Pass it On...," they wore a yellow jersey with the number "62" on the front with gray pants.
- In "Ed... Pass it On..." when Eddy's Brother (really Sarah and Jimmy) shows up in Eddy's room, Eddy gets unusually scared and pleads not to hurt him. This alludes that, prior to Ed, Edd n Eddy's Big Picture Show, Eddy's Brother abused him.
- Eddy's Brother is first mentioned in the episode "Nagged to Ed" when Eddy observes the Trailer Park and states that "Looks like a postcard I sent my brother once."
- Eddy's Brother is voiced by Terry Klassen, the main voice director for the series.
- He was the original owner of Eddy's dirty magazine collection, as mentioned in the episode "The Luck of the Ed."
- His tongue color is just normal pink, just like the Kankers.
- In Ed, Edd n Eddy's Big Picture Show, a glass in Eddy's Brother's room reads "Peach Creek Diner-2000 Best Eater." If this was in his room before he went away, it could mean that he left during, or after, the year 2000.
- He is lactose intolerant as stated by Eddy in "Ed... Pass it On..."
- In an ironic twist of fate, Eddy's Brother muttered the word "Uncle" after getting hit by his own trailer door at the end of the movie.
- Eddy's brother's character design was done by storyboard assistant and character/prop designer Cory Toomey.