|Season 1 Gallery||Miscellaneous Gallery||Season 2 Gallery|
| Character Information|
|Voiced by||Jess Harnell|
|Nickname(s)||Kooks (along with Grumpy; by Sid)|
|Age||Mid 20's (Younger than the Queen, Starchy and the 7D)|
| Episode Appearances|
|First Appearance||"The Long, Long Winter"|
|Last Appearance||"A Sneeze in Time"|
|Family|| Hildy (wife)|
Great-Great-Great Grandfather Gloom
|Enemies|| The 7D|
Grim is being portrayed in the show by not being bright in many situations, and that usually lead to many of his and Hildy's failures. Despite the fact that Hildy bosses him around he, in his heart, loves her and will do anything for her and Hildy wholeheartedly returns his feelings. In his spotlight episode "Grim the Genius", Grim attempts to become smart while trying to win back Hildy after another failed attempt to drive Queen Delightful out of her castle (and destroying their manor at the same time). He (donning a disguise) obtains the Smarty Pants Stone from Doc and Grim becomes intelligent. He then patched things up with Hildy after they together seized Delightful's throne, making Hildy queen. However, Grim's new-found smartness rejects Hildy's affections. After The 7D got back the Smarty Pants Stone from Grim, he realizes that he doesn't need it now that Hildy misses the old Grim and the two embrace (and being sent to the moon by Grumpy).
Grim's warm and childish nature is in stark contrast to his evil great-great-great-grandfather, who ruled Jollywood many a year ago.
In "Itsy Bitsy Spider Fighters", it's revealed that Grim is afraid of spiders (despite the fact he was transformed into a six-foot spider himself by Hildy) as well as ladybugs.
Grim's standard clothing consists of a gray trench coat with stars and a crescent on its left side and a black belt. Underneath the coat is a purple collared shirt and blue tie. Rounding out his outfit are black trousers and purple shoes. His hair is blue with a white lightning bolt and he has a large nose. Both he and Hildy have moles above their cheeks; Grim's on his right. As with Hildy, Grim retains some of his human characteristics when he transform into different forms.
- "Raahr! I'm dragon-y and fire breathing and stuff!" ("Grim the Dragon")
- "I can has pickle?" ("The Jollywood Jam", after he and Hildy turned into cats by Sir Yipsalot)
- "But, Hildy, it won't let go!" ("Knick Knack Paddy Whack", when he literally got a cat stuck on his tongue)
- "Excee!" (whenever he finds something great happens)
- "The Delightful Diamond Mystery"
- "Starchy Takes a Break"
- "Goldilocks and the 7D"
- "Grampa Grumpy and the Ogre"
- "Bathtub Bashful"
- "New Shoe"
- "Uncle Humidor"
- "Gingersnaps and Grumpy Snaps"
- "The Very Important Thingy"
- "Sir Yipsalot and the Mutt"
- "Big Rock Candy Flim-Flam"
- "In Yer Dreams, Pal"
- "Oh Happy Grumpy"
- "Jollyball Anyone?"
- "The Family Pickles"
- "Dr. Jingleheimer"
- "The Enchanted Forest Ranger"
- "Nicely Done and The 7D"
- "Take Care of Your Elf!"
- "Game of Grumpy"
- "They Growl By Night"
- "Planks, But No Planks"
- "Once in a Purple Moon"
- "A Royal Pain in the Castle"
- In his prototype design, Grim was originally going to have green hair instead of blue. (see right)
- Grim's Great-Great-Great Grandfather Gloom resembles Lord Grudgemunger, meaning he could possibly Grim's great-great-great grandson.