The Amazing World of Gumball - Season 3 - Eps 4: The Joy
When Miss Simian sees Gumball and Darwin joyful on Monday, she knows that something is wrong with them. She performs tests on them, but the nurse disapproves what she's doing. But suddenly, Gumball and Darwin start to infect the school with the 'Joy Virus', and it's up to Miss Simian and her tape player to cure the students.
About The Amazing World of Gumball

Title: The Amazing World of Gumball
First Air Date: 2011-05-03
Last Air Date: 2019-06-24
Status: Returning Series
Rating: 8.493/10 (from 1484 votes)
Language: EN
Seasons: 8
Total Episodes: 266
Network: Cartoon Network
Genres: Animation, Family, Sci-Fi & Fantasy, Comedy
Production Companies: Hanna-Barbera Studios Europe, Boulder Media, Studio Soi
Synopsis
The life of Gumball Watterson, a 12-year old cat who attends middle school in Elmore. Accompanied by his pet, adoptive brother, and best friend Darwin Watterson, he frequently finds himself involved in various shenanigans around the city, during which he interacts with various family members: Anais, Richard, and Nicole Watterson, and other various citizens.
Cast

Nicolas Cantu
Gumball Watterson (voice)

Christian J. Simon
Darwin Watterson (voice)

Dan Russell
Richard Watterson (voice)

Teresa Gallagher
Nicole Watterson (voice)

Kyla Rae Kowalewski
Anais Watterson (voice)

Sandra Dickinson
Granny Jojo (voice)

Kerry Shale
Larry Needlemeyer (voice)

Jessica McDonald
Carrie Krueger (voice)

Stefan Ashton Frank
Mr. Robinson / Tina Rex (voice)