Da-Dai-Oh was a giant robot with spiked maces for arms. It also had a control room in its head for Eggman, Decoe, and Bocoe. Da-Dai-Oh is also really big, measuring 300 feet tall and weighing 1000 tons.

Da-Dai-Oh appeared in episode 22 "Little Chao Lost". Eggman deploys it to help him search for a Chaos Emerald. He then spots Chris and his friends and proceeds to tell them to give him the Chaos Emerald despite them telling hem that they don't have one. Then, due to Da-Dai-Oh's weight, it slides down a mountainside and pollutes a river leading to a Chao Garden. Da-Dai-Oh is later deleated by Sonic and Sonic fixed the pollution to the Chao Garden.

E-66 Da-Dai-Oh - Sonic X/Sega