I attacked an enderman with my diamond sword enchanted with Looting III and he dropped 3 enderpearls. I then tested this in creative and found the drop rate to be 0-4 enderpearls when killed with any tier sword with looting III. Not quite sure if this is a bug or not, but I suspect it is. Thanks!
MC-16316
Enderman drops up to 4 enderpearls when killed with looting III
Resolved
Works As Intended
0
(Unassigned)
Unconfirmed
ender_pearl, enderman, looting
Minecraft 1.5.2, Snapshot 13w19a, Snapshot 13w21a
Retrieved
That is intntional, hence why it is called LOOTING III. that means the mob you kill or block you mine with a tool with this enchantment will drop more than normal.