Monsters, Inc. (2001)
In order to power the city, monsters have to scare children so that they scream. However, the children are toxic to the monsters, and after a child gets through, 2 monsters realize things may not be what they think.
Shrek 1 (2001)
A mean lord exiles fairytale creatures to the swamp of a grumpy ogre, who must go on a quest and rescue a princess for the lord in order to get his land back.