Aaahh!!! Real Monsters is an American animated television series about adolescent monsters in training, developed by Klasky Csupo for Nickelodeon. The show ran from October 30, 1994 to December 7, 1997 on Nickelodeon's main United States cable channel. The series is currently being released on DVD.
The show focuses on three young monsters — Ickis, Oblina and Krumm —
who attend an institute for monsters under a city dump and learn to
frighten humans. Many of the episodes revolve around them making it to
the surface in order to perform "scares" as class assignments. [wikipedia]