"Come closer, morsel! I smell your terror...and I hunger!"— The Defiler(src)
The Defiler was a powerful and ancient bug-like creature and the ruler of an insect colony known as the Festering Nest. The whole colony was in a dormant state, slumbering in an underground location a few steps outside Tristram. When a hero started to explore the dark secrets around town, (s)he used a bomb to blow up the covering of the Defiler's lair, revealing its entrance and awakening both the insect and her insect army. However, before the Defiler was able to do much harm to the populace, she was slain alongside her minions by the hero of Tristram.
Strong against Lightning and Holy.
Weak against Fire
The Defiler has two attack types: slashing arms and a nasty stinger. she leaves the Cathedral Map when slain, which can be dropped at a huge grave in the church's graveyard to open up the entrance to the Demon Crypts, where Na-Krul resides.