Diababa

Twilit Parasite, Diababa (覚醒寄生種 ババラント) is the boss of the Forest Temple, the first dungeon in The Legend of Zelda: Twilight Princess. It is a giant three-headed Deku Baba, corrupted by Twilight, that has taken over the temple. Once it has been defeated, Link receives the first Fused Shadow as well as the first full Heart Container.

Battle
The battle begins with Diababa having two very large Deku Baba heads. After Link defeats the pair by flinging Bomblings in their mouths via Gale Boomerang, Diababa's central head emerges from the pool of water in the room, removing the previous source of Bomblings. At this point, Ook starts swinging between platforms holding Bomblings, which Link can use to hit Diababa by using the Gale Boomerang. After Link does this, Diababa's head falls to the floor, exposing its eye to sword attacks. Link must repeat this process until Diababa is defeated or use the Ending Blow as the final attack.

In Diababa's death scene, it thrashes around, shrivels up, and its eye falls out of its socket and explodes, leaving only a Heart Container. Its body then explodes into particles of twilight, which then form the first part of the Fused Shadow.

Video
This clip was provided by lleeoo2010 at youtube. evY242etL9c&feature=related

Etymology
Diababa's English name is formed from the prefix dia- (meaning power) and the latter part of the Deku Babas' name. This could be referring to its appearance as three giant Deku Babas merged together. It could also come from the Greek word for devil, diabolos.