Command: /MobSpawner
Install: extract MobSpawner to your plugins Directory.
Usage: While standing where you want the mob, Click a mob type button and then enter a number in the popup window.
Notes: Click refresh to refresh the spawned mobs list.
Spawned mobs are a random combination of all type variations
All mobs are removed at server restart or by clicking the Destroy mobs button.
Spawning/Destroying mobs with high counts WILL cause server lag!
This was made in a day so it may have some errors but should not be game breaking.