Behemoth (Hellboy)

The Behemoth is the true and final antagonist in the 2004 film Hellboy.

Overview
The Behemoth appears in the climax of the film when Rasputin reveals to have been possessed by it the entire time. It emerges from the stab wound in Rasputin's body and grows to gigantic size, whereupon it crushes Rasputin and Ilsa. Hellboy and gang have a tough time grappling it at first, but Hellboy manages to defeat it by forcing it to eat a grenade, causing it to blow up from the inside.