Darkwing Duck (1991)

S1E30 Ghoul of My Dreams

Morgana is employing sleep sand to pilfer from the residents of St. Canard while they’re in a sleepwalking state. Darkwing intervenes to restore order but finds himself trapped in the realm of dreams. Nodoff, the ruler of this dreamland and the source of Morgana's sleep sand, aims to put the whole city to sleep and is determined to eliminate anyone who tries to stop him.