In The Amazing World of Gumball episode The Grades (season 5, episode 23), Gumball, a junior high school student, is sent back to kindergarten after his teacher, Miss Simian, discovered he failed a test the first time around, causing his Grade Point Average to be 1 point short. When Nicole drops Gumball off at kindergarten for his first day back, she tells him "Have a great, second, first day of school honey" and Gumball covers his eyes while re-entering kindergarten. He is tortured endlessly by the other students, but after arriving home at the end of the day and explaining the situation to his family, Anais, his overly-brainy sister, lectures him on how good he now has it. The very next day, Gumball finds himself enjoying being back at kindergarten, but Miss Simian learns that without Gumball, she is one student short of the school board's targets and must get Gumball back into her class or else she'll lose her job at the end of the week! After some negotiation, Gumball agrees to grant Miss Simian's request, but in order to fix his GPA, Gumball has to pass a test. Miss Simian teaches Gumball to cheat, but Gumball ends up not needing the advice and passes the test, allowing him back into Junior High.

Gumball covering his eyes upon re-entering kindergarten has become a meme, where one can have Gumball covering his eyes in anticipation of anything.

https://www.deviantart.com/furikatsuma/art/BLANK-MEME-Gumball-awaits-something-terrifying-760351894
https://www.youtube.com/watch?v=7Mgq-AvU3Xs
https://www.deviantart.com/thecartoonwizard/art/Gumball-terrified-of-the-T-rex-761366896
https://www.deviantart.com/theultimatetaskman/art/Gumball-Is-Terrified-When-Daequan-Eliminates-Self-761891291
https://sta.sh/0299c9pe5k96