Giant Ape

The Giant Ape is the Monster used by the Buenos Aires headquarters of the Organization to assist in the Ritual. It's based on King Kong, but takes on a what looks like to be a mix between a ram and ape, as it bears horns. The relative size of the ladder next to it reveals the Giant Ape to be truly gargantuan.

According to the Control Room monitors that Gary Sitterson and Steve Hadley are flicking through after witnessing Japan's ritual failure, the Argentinian sector had failed too, displaying the image of the dead and defeated monster that was supposedly sent to complete the ritual on behalf of their organization. The monster appears to lie in the bottom of a basin or basement, possibly having fallen to its death.

Since it is not part of the American ritual, the item that summons it is unknown.

Trivia

 * Even though the creature resembles a giant ape, it possesses a pair of curved horns.