Neverwinter Nights is a game where you get to act out Dungeon and Dragons, and even get to designate one player to be the all-mighty dungeon master to kind of guide the game and keep order.
But sometimes you just want to screw around.
Okay, so first enter 'Debug Mode' by pressing the ~ key and typing the command 'DebugMode 1'
Once that's successful, press the ~ key again and type in the phrase 'dm_mylittlepony'
Once that's successful, marvel at how your character is now riding one of those stick-horses and makes galloping noises.
You can also do the command again to disable it, you know, if you think that taking down an intellect devourer while holding on to a toy horse is just too silly.