Continuing on a theme of discussing random monsters I like from the Pathfinder Bestiaries: The Faerie Dragon.
They are awesome, and a great example of how a stat block can inspire non-combat encounters. Because faerie dragons are way better at escaping than they are at fighting.
@Tim_Eagon My first experience with them was getting to choose one as my familiar in Baldurs Gate 2, when college friends and I played it right about the same time I was playing my first Wizard in a D&D 3.5 game.