Firebats

Firebats is a Fire spell used by Witch Doctors in Diablo III. It is unlocked at level 5.

In-game

Channels a swarm of fiery bats, hitting enemies in a 20 yard, 45 degree cone in front of the Witch Doctor for 425% damage as Fire per tick.

Costs 150 Mana to start and 75 Mana per tick to channel, has no cooldown.

Dire Bats: instead of the swarm, summon larger bats that deal 495% damage as Fire each. Distance is increased to 40 yards, and the bats pierce through enemies.
Vampire Bats: removes the channeling cost, but the initial Mana cost increases to 225.
Plague Bats: changes damage type to Poison. As the spell is channeled, the damage grows by 25% per tick, up to 638% (that is, +50%).
Hungry Bats: instead of the swarm, launches homing bats (3 per tick) that seek enemies within 20 yards and hit them for 635% damage as Fire each.
Cloud of Bats: instead of the cone, creates a swirl of bats that damages enemies within 10 yards of the Witch Doctor for 425% damage as Fire per tick. The damage of the bats increases by 20% every second, up to a maximum of 100%, but is reset if the channeling is interrupted.

The spell is named after the Firebats, Terran flamethrower heavy infantry in Starcraft and Starcraft II.