Bukkit

Below is a list of entities that can be used inside the configuration file of version 1.4:

All entities with Spigots/Bukkits code can be found here: https://hub.spigotmc.org/javadocs/spigot/

Using anything other then a mob from the above list could cause issues. Do not do it.

Peaceful:

ArmorStand
Bat
Chicken
Cow
IronGolem
Horse
MushroomCow
Ocelot
Pig
Rabbit
Sheep
Snowman
Squid
Villager
Wolf

Hostile:

Blaze
CaveSpider
Creeper
Enderman
Endermite
Ghast
Giant
Guardian
MagmaCube
PolarBear
PigZombie
Shulker
Silverfish
Skeleton
Slime
Spider
Witch
Wither
Zombie

Other:

PLAYER

Notes:

• Use the Names Exactley
• Donky's/Mules are classed as HORSE inside the bukkit code.