Anime Fanon

Grim Adventure Time with Marceline and Irwin, often shortened to Grim Adventure Time and simply called Marceline and Irwin (マーセリンとアーウィン, Māserin to Āu~in) in Japan, is an anime series and crossover of the Cartoon Network programs Adventure Time and The Grim Adventures of Billy & Mandy (with some other cartoons represented in the series). It focuses on the titular Marceline and Irwin, and is rated TV-PG.


Marceline and Irwin are your typical teenage cartoon vampires: they "hang" out, drink red, and kick bad guy butt. Together, Marcy and Irwin-along with the rest of Underfist and many other cartoon characters-defend Endsville, Ooo, and the rest of the cartoon world from the likes of Bun-Bun, Jack O' Lantern, and other evil forces.


Main Protagonists[]

  • Marceline-The Vampire Queen of Ooo, who often visits the town of Endsville. Her best friend and love interest is Irwin, who she sympathizes with and is protective of. She's somewhat aggressive, very fast, and can transform into various monsters.
  • Irwin-A teenage mummy-vampire who lives in the town of Endsville. He is a member of Underfist, a team of supernatural heroes, and is more capable than he usually lets on. He's very close to Marceline, and has a deep regard for her, as she sort of saved his life in a way.

Main Antagonists[]

  • Bun-Bun-An evil marshmallow bunny from the Underworld. Using the "lights of the Underworld", he often tries to bring chaos to the world and seek revenge on the Underfist team for ruining his attempts at taking over the world.
  • Candy Army-Bun-Bun's army, which he tend to use to do his dirty work.

Special Characters[]

  • Jack O' Lantern-An evil prankster who also wishes to rule the world. He often works with Bun-Bun, and most episodes featuring him are more serious in tone.
  • Underfist-A team in which Irwin is part of, which also consists of Hoss Delgado, General Skarr, Jeff the Spider, and Fred Fredburger. The occasionally show up to help Irwin and Marceline, but they don't appear often.

Supporting Characters and Extras[]

  • Grim
  • Billy
  • Mandy
  • Nergal Jr.
  • Dracula
  • Finn
  • Jake
  • Ice King
  • The Kids Next Door
  • The Powerpuff Girls
  • Princess Morbucks
  • Dexter
  • Mandark
  • Steven Universe
  • The Crystal Gems
  • Mystery Inc.


Character Japanese Voice Actor English Voice Actor
Irwin Hikari Yono (Speaking), Romi Park (Singing) Vanessa Marshall
Marceline Toshimi Kanno Olivia Olson
Bun-Bun Koichi Yamadera Dave Wittenburg