Caleb is a young boy Uncle Grandpa was helping in Tiger Trails with a battle against the Evil Wizard. Unfortunately for Caleb, Uncle Grandpa forgot about the wizard battle when he went on a quest to find his friend Giant Realistic Flying Tiger.
Cheerleader appeared in New Kid sitting at a lunch table with a jock and a basketball player.
One of the main characters from Cartoon Network's Dexter's Laboratory who was at The Grampies.
Duck Head Donnie
Duck Head Donnie is a kid that appeared in the episode Nickname.
Eddie is a teen boy that appeared in the short Evil Wizard. The Evil Wizard seems to be fixated on ruining Eddie's life. However, Eddie ended up benefiting from the Wizard's attempts at ruining his life and ended up finding a $20 bill stuck to a $100 bill.
English Muffinz is a teenage pop star that appears in Tiger and Mouse. Giant Realistic Flying Tiger and the Mouse are infatuated with him. After observing the bad influence that the Mouse has on Giant Realistic Flying Tiger, Uncle Grandpa plots to break them up by kidnapping English Muffinz and forcing him to date one of them. After Giant Realistic Flying Tiger kills the Mouse, Uncle Grandpa uncuffs him and instructs him to bring her back by 5:00 A.M. However English Muffinz runs out the door as soon as he is freed, and calls for help as Giant Realistic Flying Tiger chases after him.
G-Dog is part of Kid Cousin's crew and appeared in the episode Ballin'. He is voiced by Kevin Michael Richardson.
Gregory is a kid that appears in Aunt Grandma. Uncle Grandpa performed a musical number about fishing for him to get him interested in going on adventure to get a fish for his fish bowl, but Aunt Grandma came and simply gave Gregory a goldfish to help him fill his fish bowl.
Helga is a kid who appears in Aunt Grandma. Uncle Grandpa is about to help her learn how to play hockey by taking her on an adventure, but Aunt Grandma comes in and helps Helga gather courage to learn and play hockey by giving her a hockey stick.
Henry is a kid that appeared in Perfect Kid. He needed help with his science fair project, but Uncle Grandpa was being attacked by Austin 2.0 at the time and couldn't help him.
Ice Cream Shop Cashier
Ice Cream Shop Cashier is a cashier in the Ice Cream Shop that only makes his appearance in "Uncle Grandpa Sitter". He tries to refuse Pizza Steve anymore free samples, but Pizza Steve uses Giant Realistic Flying Tiger to scare him into giving him more free samples.
Isabella is making a inventor that only makes his appearance in "Inventor Mentor".
He appeared in Vacation as one of the islanders who was attempting to get Uncle Grandpa's help with stopping an active volcano from erupting.
Nameless Boy with Ice Cream was in Not Funny and was attacked by Laugh Gremlins.
Nameless Boy with Lightning Bolt Shirt
A kid shown to go to school with Dennis in New Kid and is to be good friends with Rosie and the Nameless Ice Cream Kid in Watermelon Gag.
Nameless Boy with Life Vest
Nameless Boy with Life Vest appeared in the "Fear of Water" comic in Uncle Grandpa No. 1. He was afraid of water at first, but after Uncle Grandpa takes him on a crazy adventure into the ocean, the boy gets over his fear and actually ends up enjoying the water.
Nameless Girl with Blonde Hair appeared in the comic "Lemon Moo" in Uncle Grandpa No. 4. Uncle Grandpa helped her turn her lemonade stand into a successful business.
Nameless Girl with Blue Dress
Nameless Girl with Blue Dress was in the UG Christmas Special. She was part of a hypothetical reality Lawrence showed Uncle Grandpa to reveal what would happen to Belly Bag if he weren't in his life. In the hypothetical reality, the girl has Belly Bag stuffed in a drawer and never takes him out.
Nameless Girl with Brown Hair
Nameless Girl with Brown Hair is a nameless girl that appeared in Fishing with Uncle Grandpa in the Bass Fishing segment. She watched as Uncle Grandpa debated with himself about pushing a lever that said "DO NOT PUSH!".
The Not Now Kid is a nameless boy that appeared in "Fishing with Uncle Grandpa". He accompanied Uncle Grandpa during his adventure, despite being dismissed with "Not now, kid" every time he called Uncle Grandpa's name.
Stephanie is an employee of Uncle Grandpa Land. She had a crush on Jimmy, but that quickly went away after he hardcore rejected her for his disturbing obsession with churros as seen in Uncle Grandpa Land.
Steven Quartz Universe
One of the main characters from Cartoon Network's Steven Universe who didn't get a grampie at The Grampies.
Zack is a kid that appears in Aunt Grandma. Uncle Grandpa attempted to help him learn how to play guitar by bringing him on an adventure into outer space, but Aunt Grandma was able to successfully help him more successfully by just giving Zack his very own guitar to practice learning on.