Classic Cartoons:
* Garfield: The cynical, lasagna-loving cat.
* Goofy: Mickey Mouse's goofy and clumsy best friend.
* George Jetson: The father in "The Jetsons," a family living in the future.
* Gaston: The arrogant and vain antagonist in "Beauty and the Beast."
* Gargamel: The evil wizard who tries to capture the Smurfs.
Modern Cartoons:
* Gumball Watterson: The mischievous and playful cat from "The Amazing World of Gumball."
* Glimmer: The princess from "She-Ra and the Princesses of Power."
* Grogu (Baby Yoda): The adorable creature from "The Mandalorian."
* Gonzo: The eccentric and lovable muppet from "The Muppet Show."
* Gerald Johanssen: The best friend of Tommy Pickles in "Rugrats."
Other Notable Characters:
* Gadget Hackwrench: The ingenious inventor from "Rescue Rangers."
* Gidget: The surf-loving chihuahua from "The Secret Life of Pets."
* Grumpy Cat: The internet sensation known for her perpetually grumpy expression.
* Ginny Weasley: A character from the Harry Potter series who is a Gryffindor witch.
* Gizmo: The adorable Mogwai from "Gremlins."
This is just a small sample of cartoon characters that begin with G. There are many more out there, depending on the specific genre and era you're interested in!