Great Mazinger:

A warrior from Mycenae. He was sent by the Mycenaean Empire to overlook the developments between Dr. Hell and Mazinger Z, making sure they went according to their plans. Though he helps out Dr. Hell on occassion, his true loyalty is to Mycenae.

Shin Mazinger:

The soldier who lead the Mycenaean troops garrisoned on Earth. His upper body is that of a green-skinned human, while below the waist he is a sabre-toothed tiger. After he and the rest of Mycenae were defeated by Zeus, he sealed himself into a statue and hid within the depths of Bardos Island, so that he could revive at a later date and reclaim Bardos.