https://screenrant.com/are-you-afraid-of-the-dark-ghastly-grinner-scary-episode/

Despite being a children's show, Are You Afraid of the Dark? has one of the scariest episodes in horror TV history, and it still holds up.

The scariest episode, to me, is 'Tale of the Night Shift' from Season 5 where an old vampire uses a hospital as his source for blood. The episode featured blood which was rare for Nickelodeon.

The creature looked like a cross of Radu from Subspecies and Vigo from Ghostbusters II.