Celebs Who Secretly Played Characters on SpongeBob

Amy Poehler as Grandma 1 of 16

The popular Spongebob Squarepants cartoon already features hilarious writing and voice acting, but the show is even better when there's a celebrity guest star. Check out the whole list to see which of your favorite celebs voiced characters on the show!

The Parks and Recreation star and SNL alumn lent her voice to the roll of Grandma in the season 4 episode "Have You Seen This Snail?".