This papercraft is Grendel (Guride Garude), the cycloptic Green Gigas, based on the role-playing video game Skies of Arcadia (released in Japan as Eternal Arcadia), the paper model is created by colinot.
Unlike the other Gigas, he doesn't seem to have any sort of fail-safe function in place as instead of just stopping in the event of its master's death or critical injury, it goes beserk and destroys everything in this path. In the case of the wandering Rhaknam and still-awake Yeligar, Rhaknam doesn't cause destruction intentionally and Yeligar was successfully stopped and sealed fairly easily, implying that it didn't go beserk like Grendel did.
Grendel is a giant humanoid with a hollow chest. It lay sleeping in the Ixa Taka forest until it was awakened by the King of Ixa Taka who used it against the invading Valuan Armada until he was defeated. After De Loco fired his Test Cannon at the king's ship, the king fell unconscious, thus Grendel lost its sanity and ran amok. Grendel was stopped when the Little Jack caused it to fall into a lake. King Ixa Taka then gave Vyse and the gang the Green Moon Crystal.
After the Rains of Destruction fell thousands of years before the adventures of Vyse and crew, most of the Gigas receded by command of their masters or their deaths. However, Grendel continued his rampage, destroying what was left of his masters kingdom. It took the work of the Silvites to put him back to sleep. [Source: wikia]
You can download this papercraft model template here: Skies of Arcadia - Grendel Free Papercraft Download