Are You Afraid of the Dark? S04 E09 The Tale of the Ghastly Grinner

"Submitted for the approval of the Midnight Society, I call this story..."

Ethan wants to be a comic book artist, but his submissions are constantly rejected by companies. One day, he's invited to a comic shop, where he gets the only copy of the comic ""The Ghastly Grinner."" He accidentally brings the supervillain to life and it starts turning everyone into giggling mindless idiots.