Do some mobs have hidden behaviours?
Do mobs have hidden, intelligent behaviours? I once noticed that an Endermen picked up a block from near my mine entrance, and it collapsed, and at other time a Zombie picked up an item from my chest. Were they only coincidences?
Solution 1:
No, mobs don't have hidden behaviors unless you count the killer bunny and mobs needed to summon by command. There have been removed mobs no longer in Minecraft that may have been considered secret with different behaviors. There is plenty more on mobs on the Wiki. http://minecraft.gamepedia.com/Mob