Originally labelled Grim and Evil, the series was a combination of two shows in one. In each show a segment of Evil Con Carne was put between two Grim cartoons. In 2003, CN decided to give each short their own full length show. Evil Con Carne was subsequently canceled.
The GA universe, in addition to regular violation of the laws of physics, also contains a number of historical variations. Abraham Lincoln is President and a personal friend of Billy. Also, the world police organization is not the United Nations, but the League of Nations (disbanded in 1946 in reality).
Another unique aspect of the show is that episodes often end with the distruction or alteration of the world, or with the disappearance or horrific transformation of the main characters. These changes do not carry over to the next episode, however. Often the episode will end with no resolution at all. For example, in Halls of Time, Billy, Mandy, Grim and Erwin all disappear forever when their hourglasses in the halls of time are turned upside down. In Chocolate Sailor, Billy is turned into a large quantity of chocolate syrup, and in Sickly Sweet, Mandy is turned into a giant monster by an evil mask. Because the producers can compromise the safety of the characters in each episode, the show can avoid the cliché that good always triumphs.
The GA universe is also the Evil Con Carne universe: the characters meet, briefly, in the episode Chicken Ball Z (a parody of Dragon Ball Z.) In the third season episode Skarred For Life, General Skarr, at least, finally meets the GA characters in what could be seen as a full crossover. The series is noted for its parodies, notably Harry Potter, and for quote references, like "Scooby-Doo" and "The Wizard of Oz".
One humourous premise is the baseless sexism of the boys: Billy and Irwin tell Mandy that she cannot do something with them because she is a girl; they then demonstrate their own ineptitude or she shows her superiority.
File:Billy-gaobm.jpgBilly does something stupid...againBilly (diminutive for WilliamTemplate:Inote) is an astonishingly incompetent red-headed child with an oversized nose. He exemplifies the concept of "ignorance is bliss". Prone to surprising (if nonsensical) fits of rage, he is a hyperactive, nose-picking, flatulent child with a knack for causing disasters by experimenting with Grim's various supernatural items. He is voiced by actor Richard Steven Horvitz.
File:Bill mandy.jpgMandy at one of her "good" daysMandy is Billy's constant companion: a blond, noseless girl with an acerbic attitude and evil personality and often surprising intellect and knowledge of the supernatural. She usually never smiles, but she did in My Fair Mandy, which caused reality to twist and bend so that they became stuck in a The Powerpuff Girls-like universe. She frequently appoints Grim to perform humiliating chores. She is so clever that stories end with her solving all problems in some incredible manner involving nothing but her wits and personality. She is very rude to practically everybody, even her parents. Voiced by Grey Delisle, who lends a characteristic somber and gothic tone to this character.
File:1163428343.jpgBad to the bone (literally) - GrimGrim - The Grim Reaper, who lost a bet to Billy and Mandy and is fated to be their "best friend forever" (effectively, their slave), a task he suffers with no small amount of disdain and mockery from other supernatural creatures. His accent and some lines suggest he is Jamaican, although he was apparently a child at the time of the neanderthal. Voiced by Greg Eagles.
Occasional
Billy's parents - Billy's mom, Gladys, hates Grim to the point of psychotic obsession—she considers him a threat to her son's safety. She also gets very twitchy, and often doesn't take her medication. Billy's dad, Harold, strongly resembles his son in physique, personality, and intelligence. He is convinced, wrongly, that his son is a genius, despite evidence to the contrary. The parents' relationship seems to be a romantic and loving one, as Billy's dad has his arm around his wife's shoulder in the episode Whatever Happened to Billy Whatshisname??. Harold is also voiced by Richard Steven Horvitz, and Gladys is voiced by Jennifer Hale.
Milkshakes - Milkshakes is Billy's cat, a rosy-pink feline who frequently is put into unusual situations by the supernatural events that occur in his owner's life. Whether possessed by Grim, mind-controlled by an intelligent parasite, or hanging by it's claws from the branches of a tree, Milkshakes shakes it all off with a calm meow. His stoic attitude is at odds with that of his owner.
Saliva - Saliva is Mandy's dog, although his behavior is closer to that of Billy, in that he appears to have lower-than average intelligence, motor skills, and awareness. Also like Billy, he can exhibit uncharacteristic rage on occasion. His name echoes his propensity for drooling.
Irwin - Irwin is Billy's sole male friend of his own age, a nerdish character who longs to gain the admiration (and affections) of Mandy (in the episode Scythe for Sale, in a attempt to make Mandy like him, he uses Grim's scythe to hypnotize her and make her his obedient love slave), and aspires to be cool (though he frequently fails in both goals, typically embarassing himself). Despite his friendship with Billy, he also seems to harbor some subdued hatred or jealousy towards his incompetent friend. He is voiced by Vanessa Marshall.
Pud'N - A physically weak and easily terrified classmate of Billy and Mandy who is often either the victim, instigator, or both, of some terrible trauma.
Sperg - The local bully, often seen tormenting Billy, Irwin, or Pud'n. He is sometimes the focus of gags based on his uncharacteristic love of dancing and "girly" music.
Mindy - The iconic "popular girl", obsessed with proving her worth to Mandy, who exhibits little care for the seemingly spoiled child.
Jeff - Billy's "son", a giant spider who came to believe through imprinting that Billy was his father; he is unusually kind and well-mannered, prone to giving gifts and apologizing profusely. His explanation is that he has an abnormally small "mean gland". Billy is terrified of Jeff to the point of hatred, though Jeff is either blissfully unaware of this, or so loving that he ignores it. In one of his later appearances, it is suggested that Jeff is actually female, as he gives birth to hundreds of baby giant spiders.
Minor
Hoss Delgado - Hoss is a Spectral Exterminator, a hunter of paranormal creatures. Modeled after Ash, the protagonist of the famed Evil Dead horror movie trilogy, Hoss possesses only one hand with the other replaced with a mechanical hand that transforms into a fist, cannon, or (much like Ash) a chainsaw. He first encountered Grim with the intent of exterminating him, believing that Billy and Mandy were being held hostage. After he learned the truth of their relationship, he congratulated the two children and left (apparently to battle a werewolf in Canada). He has since returned on several occasions to both aid and hamper (such as being convinced that a hair-covered Billy was a sasquatch) the citizens of Endsville, occasionally after being summoned for help.
Nergal - A powerful being from the center of the Earth who is obsessed with making friends, he has the power to transform others into his unwilling friend-slaves. Having married Billy's aunt Sis in "Love is Evol Spelled Backwards", making her his wife, he improbably has a son by her in a later episode. Voiced by famed British character actor David Warner of Freakazoid fame. Nergal is the actual name of a Babylonian deity.
Nergal Jr. - Nergal's son by Billy's aunt Sis, and thus Billy's half-demon cousin. He has the power to transform into other people (although his bright green eyes and glasses remain), and has an apparently horrifically gruesome true form that is never seen on-screen (although, on the intro screen, where you see Nergal on the left, where you see a smaller version of him, it looks like Nergal Jr. in his true form). His arrival in the series is comically improbable, suggesting that he was born and grown to his apparent age (equal to Billy and Mandy) in a matter of months, or perhaps weeks. It is unclear on how the two sired him; some fans have suggested that they did so by coitus (a la Rosemary's Baby). (Quotable Quote- "I am so sick and tired of everyone calling me a freak! It makes me mad! So very mad!"- at this point, tentacles come out the back of Jr.'s head).
(General) Skarr - A guest star from the Evil Con Carne program and animated shorts that spun off from The Grim Adventures of Billy and Mandy. Retired from villainy, he moved into the neighborhood in the epsiode "Skarred for Life".
Eris - Loosely inspired after the matron deity of the Discordianism, here portrayed as a vindictive blonde rival to Grim, who delights in causing all kinds of chaos. Her accent and mode of speech is prone to sudden shifts, from a stereotypical valley girl to a refined British woman (probably a reference to Madonna, known for her coquettishness and periodically reinvinting herself. Eris is even drawn with a similar gap in her front teeth in her second appearance. Madonna became quite the Anglophile following a tour of Great Britain, even adopting a clipped Brit accent of her own, which might explain Eris' affectation.).
Nigel Planter - A spoof of Harry Potter, who is in love with Mandy. He was soundly beaten by a one-eyed troll after taking the credit for Mandy's acts of sabotage against a rival dormitory.
Irwin's parents - Referred to only as "Irwin's Mom" and "Irwin's Dad." While Irwin's father is a normal middle-aged man, Irwin's mother is a mummy. She lives in a sarcophagus in the basement of Irwin's house, which for unexplained reasons looks like an Egyptian tomb. Their marriage is based on love (similar to Billy's own parents, Harold and Gladys), and the many improbable facets of their relationship are explained by Irwin's father as "questions which don't need to be answered."
The Grim Adventures of Billy and Mandy in Other Languages
The Grim Adventures of Billy and Mandy is the title of a song by Voltaire (an obscure AmericanGoth band) concerning a brain-eating meteor from the sky. The song is alternatively titled Brains.
