Athame

The Athame is a silver dagger. Against most mobs or other players, it does 1/2 hearts of damage, but deals bonus damage to Endermen. The Athame is capable of killing an Enderman in just two non-critical hits. Its item ID is 1329.

Crafting requires a single Silver Ingot and a Stick, which means it can be crafted without the need for a Crafting Table.

An Athame can be enchanted with Disjunction to cause even more damage to Endermen.

It is also very good when in an enchanting table; one level can give you a level 2 enchantment.