Eddy's Brother is the older brother of Eddy. He was previously an unseen character, and is the only one of the series adults that has been both seen and heard. He has a deep voice and a room that Eddy hopes to inherit and reside in. His room is complete with a car and all kinds of memorabilia and strange items. For example, he owns a pet snake (stated by Eddy that the snake has gotten loose), a giant dusty taxidermy camel, a brick-covered window, a bed that folds-up into the fridge, and a (now broken) trophy (unknown for what, but it might be chewing ice cubes because Eddy said before Ed saw the trophy that he was a whiz at chewing ice cubes), however in Ed, Edd n Eddy's Big Picture Show it is seen on the floor unbroken.
He is probably over 18 due to the fact that he owns a car and doesn't live with his parents. He may have a kinship with the Kanker Sisters, as he was able to set Eddy up to go to their trailer for a prank, but this is unlikely because the Kankers moved in after Eddy's brother was gone (not to mention the way the sisters treated him in the movie). He also tries to scam everyone similar to Eddy, but much more successfully. His room is guarded by a chained lock, pieces of wood nailed to the wall, and a falling safe, and it was also camouflaged to blend in with the rest of the wall. The door to his room is hidden behind wallpaper for some reason.
In some of the early seasons, many fans didn't think he was "real". His first and only appearance was in Ed, Edd n Eddy's Big Picture Show. He is one of the few people whom Kevin fears probably because of his strength and due to the stories Kevin has heard about him. Eddy's Brother wears a red plaid jacket, and a brown cap. He also has some hairs on his rather large chin, and he also has three hairs sticking out from the back of his head just like Eddy. He resides in the coastal theme park Mondo A-Go Go in a trailer (Eddy's Brother's Trailer).
There had been clues about Eddy's older brother throughout the show: in season one's "Fool on the Ed," it is learned that Eddy's brother showed him how to make the special-recipe El Mongo Stink Bomb, "before he went away," and in season two, there's a glimpse of a picture on Eddy's wall - 2 boyish silhouettes, one bigger than the other. The biggest clue lies in the "Ed in a Halfshell," where Eddy sets himself the task of making Jimmy his protégé, and we learn that Eddy himself was molded in just this way by his older brother.
Season three provides an abundance of brotherly details, starting with the episode "O-Ed Eleven" where we get to see hallowed ground- Eddy's brother's room. The decor is just as unique and twice as bizarre as Eddy's room, and gives hints towards how multifaceted he appears- from bouzouki playing to bricklaying, to chewing ice cubes to ticking off Eddy, his big brother has a lot of unknown tales to be told. In "An Ed is Born", Eddy gets a care package that shows that his brother thinks of him as a baby, and perhaps Eddy's "No more beating up little Eddy!" comment at the end gives us a pretty good idea of just where he got that knack for shoving around his pals. It's impossible to talk about Eddy's brother without mentioning the stir caused by rumors of his return in the episode "Ed... Pass it On..." Not until the Kankers went on their latest hissy fit had the whole neighborhood been in such an uproar; Rolf digs a moat and knits a very special offertory vest to protect his chickens, Nazz gleams at the prospect of having someone as rad as Eddy's brother to hang with, and even tough-guy Kevin disintegrates into a groveling coward as he ponders the implications of Big Brother's return. Eddy's brother seems to give off a foreboding aura.
He sent Eddy a box of baby-related items like a pacifier, a diaper and a rattle in "An Ed is Born," which shows less chance that Eddy is actually respected by his brother (social issue). His true nature is shown in his first on-screen appearance in Ed, Edd n Eddy's Big Picture Show.
In Ed, Edd n Eddy's Big Picture Show, after Edd analyzes all of stories Eddy has told him of his brother, Edd comes to the conclusion that Eddy's Brother is a prankster. However, during the end of the movie, Eddy's Brother's true colors are revealed: he is, indeed, a huge jerk and is, surprisingly enough, the main antagonist of the movie. He makes fun of Edd by calling him Eddy's girlfriend, and then proceeds to bully Eddy, continuing the stereotypical dysfunctional older brother/younger brother relationship, although it must be noted that his beatdown, though cartoonish in several ways, shows that he is a very sadistic person, to the point of being downright evil, as the things he did to his little brother were completely unprovoked, and he just played "Uncle" as an excuse to hurt his little brother. His experiences with Eddy may also have severely injured his little brother. However, this ends when Ed pulls out a hinge that is barely holding onto Eddy's Brother's trailer door and it ends up slamming him in the face (with Eddy still clinging to the door in fear) and knocking him out cold. While the Eds get carried off, the Kanker Sisters are seen dragging him inside his trailer.
- 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.
- Four of the kids had widely differing opinions of Eddy's Brother:
- Rolf used to fear that Eddy's Brother wants to steal his chickens (he may have done this before he went away).
- Nazz used to adore Eddy's Brother, most likely because of Eddy's over-the-top characterization of his lifestyle.
- Kevin used to live in fear of Eddy's Brother, based on stories he's heard about him.
- Sarah was completely indifferent about Eddy's Brother because of her belief that "brothers are stupid" (like Ed).
- 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."
- Like most of the adults, Eddy's Brother's actual name is never revealed. In the movie, he is always referred to as "Eddy's Brother" or variations of this. He is credited as "Eddy's Brother," and closed captions also refer to him as "Big Bro."
- The Kanker Sisters may have a crush on Eddy's Brother evidenced by their comments and actions near the end of the movie.
- Eddy's Brother asks Eddy if "Mom and Dad know [he was] here" while behind his doors, which may hint he has a bad relationship with his parents. However, he may have simply been surprised that Eddy was there without his parents.
- The postcard he sent Eddy read "Having a blast! From, Big Bro." If he sent that to Eddy, he might actually care about him a lot more than it shows in Ed, Edd n Eddy's Big Picture Show. Then again, the postcard's purpose could be to only brag about his job at the amusement park.
- It is unknown what his job at Mondo A-Go Go is.
- His tongue color is just normal pink, just like the Kankers.
- In the movie, the broken trophy in Eddy's brother's room is not broken, but this means that Eddy repaired it at some point after Ed broke it in "O-Ed Eleven."
- 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.