There’s a specific window of Nicktoons that a certain generation of Millennials hold in dear, powerful nostalgia. Nickelodeon went through a phase in the ‘90s that was rife with charming characters, zany animation, and touching stories — whether it was through the eyes of preverbal infants like in Rugrats, or through weird teenage monsters trying to learn the ropes of scaring like in Ah! Real Monsters. But everyone’s favorite animated depiction of city block life was Hey, Arnold! This popular Nicktoon featured a kid named Arnold, raised by his whacky grandparents, navigating what it means to grow up in the city.