Wraith (Diablo II)

Wraiths are a type of undead creature.

Lore
Wraiths are ethereal physical manifestations of tortured souls from the planes of the Burning Hells. They materialize to attack as skeletal, bat-winged creatures, ringed by an aura of eldritch energy.

Often called "ghosts" or "evil spirits" by mortals, Wraiths are driven by an intense hatred for the un-suffering living. They often inhabit the darkest dungeons, having either been drawn there by the imprint of pain and suffering, or summoned and bound by powerful Mages to serve as unwilling guardians. These ethereal creatures can pass through solid objects, and contact with a Wraith can quickly drain one's life force. Spellcasters and other energy-reliant mortals may not only be drained of health, but are also left defenseless as their mana is quickly spirited away to slake the spiritual thirst of these damned souls.

In-game
Wraiths have the Mana Burn ability which they use with 45% chance. The base Wraith appears in Jail 1-3 and Cathedral.

Development
Wraiths have an unused spell casting animation, it's unknown however what magic they would have used.