Grumpy Gerbil Share definition Flag a middle aged man who is a social studies teacher you HATE. he is annoying, unfair, and rude. me: *goes to the bathroom*Grumpy gerbil: WHERE R U GOING!!!!! NOOOOOOOOOO YOU ARE BADDDD Grumpy Gerbil by thisiswhomadethis <3 May 13, 2021 0 0 Get merch Get the Grumpy Gerbil mug. Buy Now — $32.95 See more merch