Crafting requires a single Silver Ingot and a Stick, which means it can be crafted without the need for a Crafting Table. The Athame does little damage against most mobs in Minecraft, but it excels at killing Endermen, requiring only two hits to kill one from full health. This makes it very useful for farming Ender Pearls, but a mediocre weapon against any other hostile creatures the player may come across.
It is also enchanted very well; one level can give you a level 2 enchantment. However, due to its low damage rating, it's not recommended to spend experience on the Athame unless you are specifically hunting Endermen for the Ender Pearls.