The Grim Adventures of Timmy & Tootie is a spin-off about what would happen if Grim from "The Grim Adventures of Billy and Mandy" never met Billy and Mandy but Timmy, Tootie, Chester, AJ, Molly, Cosmo, Wanda and Poof instead. And soon it results in supernatural adventures involving fighting supernatural evil and when Timmy and Molly's wishes go supernaturally wrong.
New Characters
- Grim - Grim is forced to be Timmy and Tootie's best friend forever, after Timmy, Molly and Tootie defeated Grim in a scare off (by Poof transforming them into a three-headed super reaper). He is a skeleton carrying a scythe. He knows Cosmo and Wanda and many dead beings and ghosts. He also has many enemies. He lives at Timmy's house disguised as a cat.
- Ember McLain - Ember is an antagonist from Danny Phantom. She has the same job. Not until later she becomes good (mostly because everytime she tried to attack Grim, Timmy and Tootie something else was doing just that so she just gives up and helps those "dipsticks"). She has a crush on Timmy and acts as a rival for Tootie. It is shown that she can shapeshift into anything.
- Nergal - A lonely black creature from the center of the Earth. He kidnaps all the kids at first, but finally marries Billy's Aunt Sis.
- Nergal Jr. - The son of Nergal. He acts as a love interest for Tootie.
- Jack O' Lantern - a maniacal prankster who works on Halloween and April Fool's day...Grim actually decapitated him and now he wears a pumpkin for a head! He was also briefly destroyed by The April Fool.
- Fred Fredburger - a green furry elephant from the Underworld. He is dumb, and is best friends with Gir, Cosmo and Chester.
- Hoss Delgado - Hoss is a spectral exterminator; a hunter of paranormal creatures. He possesses one real hand and a mechanical one, the latter of which can seemingly produce any tool he desires, most commonly a metal fist or a chainsaw-launching crossbow. He is the take-no-prisoner figure from the show, though in most episodes he acts in a clumsy and/or goofy manner. He first distrusts Ember, but this dissipates as the series progresses.
- Dean Toadblatt - Dean Toadblatt is the headmaster of Toadblatt's School of Sorcery, and a spoof of Albus Dumbledore. Toadblatt is a large, humanoid toad wearing a purple wizard's robe.
- Lord Moldybutt - A spoof of Lord Voldemort. Saying Lord Moldybutt's name causes things to break. In consequence, people call him "he-who-should-never-ever-be-named".
- Sir Raven - Sir Raven is a big raven in a somewhat rich getup. He is seen in a stereotypical Victorian living room, complete with a warm fireplace and a cushiony arm chair. He randomly appears in some episodes and narrates part or the whole story. He has an odd tendancy to scream repetitions of the last word he said.
- The Secret Snake Club - Three nerds who want to eliminate all cool kids so nerds can rule the world. Timmy, Chester, A.J., Sanjay and Elmer were briefly members of the group until they found out what the club was actually doing.
- The Boogeyman - The Boogeyman--Boogey for short--has been Grim's archenemy since their high school days. He is also his rival when it comes to scaring people, but he's not as good as Grim is.
- Zim - Zim is a irken invader and anti-hero from Invader Zim. He is Jimmy Neutron's closest friend. He distrusts Grim at first, but he becomes his ally and acquaintance after realizing what he just done poorly to the Underworld. He also carries a spear and wields it in combat.
- Gir - Gir is Zim's hyperactive SIR unit robot also from Invader Zim. He is one of Fred Fredburger's best friends.
- Almighty Tallest Red - one of the leaders of the Irken Armada who despises Zim. When he and Purple come to Earth, they distrust Grim at first, but they soon become his acquaintances after Grim tells them what Zim just done poorly to the Underworld. He and Purple always argue with each other and get into fights, but that never endangers their friendship. He is also more intelligent than Purple.
- Almighty Tallest Purple - the other leader of the Irken Armada who also despises Zim. Although he usually obeys Red, he loses his mind in front of all things silly. He also likes doing flatulent sounds with his underarms, much to the annoyance of Red. He and Red always laugh at Zim's bromance with Jimmy.
- James "Jimmy" Isaac Neutron - a boy genius from Retroville who is Timmy's Best Friend and Zim's closest friend. He and Zim share a strange bromance with each other.
- Norbert and Daggett - two beaver siblings from The Angry Beavers. they are Rodney J. Squirrel's best friends. they always hang out with Zim, but they are unaware of his bromance with Jimmy.
- Rodney J. Squirrel - a small red squirrel with buck teeth, a light orange stomach and mouth and red nose. He's from the Cartoon Network show Squirrel Boy. He lacks good judgment and critical thinking, and often finds himself in many sticky situations due to his irrationality. He is Norbert and Daggett's best friend, as he hangs out with them a lot when Zim is not around. He actually knows Zim's bromance with Jimmy.
- Yumi Yoshimura - a cynical, sarcastic, rough and tough punk rocker who is Tallest Red's girlfriend.
- Ami Onuki - a peppy, optimistic and cute schoolgirl who is Tallest Purple's girlfriend.
Cast
- Tara Strong as Timmy Turner, Poof, Ember McLain, Lauren, Tad, Britney Britney, Gir
- Greg Eagles as Grim
- Daran Norris as Cosmo, Mr. Turner, The April Fool, Dean Toadblatt, Anti-Cosmo, Jorgen von Strangle
- Susanne Blakeslee as Wanda, Mrs. Turner, Anti-Wanda
- Grey DeLisle as Tootie, Molly, Swizzle, Vicky, Chad, Veronica, Yumi Yoshimura
- Dionne Quan as Trixie Tang
- David Warner as Nergal
- Debi Derryberry as Nergal Jr., Jimmy Neutron
- Dee Bradley Baker as Sanjay, Elmer
- Jason Marsden as Chester McBadbat
- Gary LeRoi Gray as A.J.
- Tom Kenny as Wiggly, Cupid
- Billy West as Viper, King Cobra
- Julian Stone as Sir Raven
- Wayne Knight as Jack O' Lantern
- C.H. Greenblatt as Fred Fredburger
- Diedrich Bader as Hoss Delgado
- John Kassir as Lord Moldybutt
- Eric Bauza as Foop
- Chris Kirkpatrick as Chip Skylark III
- Jay Leno as The Crimson Chin/Nega-Chin
- Fred Willard as the Boogeyman
- Richard Steven Horvitz as Zim, Daggett, Rodney J. Squirrel
- Nick Bakay as Norbert
- Wally Wingert as Almighty Tallest Red
- Kevin McDonald as Almighty Tallest Purple
- Janice Kawaye as Ami Onuki
Episodes
List of The Grim Adventures of Timmy & Tootie episodes
Trivia
- Most of the Grim Adventures characters and Jimmy Neutron are redesigned to the style of The Fairly OddParents, while the other characters from other shows remain in the same style of the shows they came from.
- Lord Moldybutt is redesigned to look more like Lord Voldemort from the Harry Potter movies.