Dai Dai appear at the tail end of episode 56 of the Grendizer, was the episodes 2nd Beast, after Zami Zami, and was the 61rst Monster to appear in the show; resembling a quadrupedal Dragon, having gray color Bird like head with a moon crescent shape, with a green color neck and long tail; torso was light green with black bands on the side of the neck, and a turquoise mid to lower body section; the upper area of of all four legs was Blue Green in color, with the lower legs been black, ending in sharp talons, hind legs had diamond shape knee plates; finally it had Wings which were dark and light yellow in color.

Besides flight & its massive claws, Dai could fire a Beam from its mouth & missiles from the portholes in the wings.

Trying to redeem himself from his failure and getting back at Umon, Zuril heads to Switzerland and holds Prof. Shubyler (a friend of Umon) and his Assistant (Elza); after a brief encounter with Umon, she request (under threat) that they leave, as the professor is busy preparing for the conference. Later, at the event Zuril (disguise as Shubyler )takes the stand his and attacks both Umon and his Satellite, considering it a threat to the world, even alluding Umon may be in aligned with the Invaders. As the conference continues, Duke takes off on the Grendizer and flies to Switzerland at top speed. As the audience demands evidence to such accusations, the Beast Dai Dai appears and attacks; Koji, Maria and Hikaru take off on the Spazers while Zuril continues the attacks against Umon, and (FOR SOME DUMB REASON) the audience agrees and decides to destroy the Satellite (For a room full of smart people, they were played as fiddle). After the conference, Umon demands answers from Shubyler who tells him he is too ambitious and, leaves a distraught Umon behind.

Side Note: Did I said they were played like a fiddle? No, nononono, Lads!!! Zuril played them like an Orchestra in Stupid - High Stupid, that is. Yeah, that sounds about right.

Up in the sky, the battle between the Spazers and the Beast continue, when Grendizer arrives, slicing the Beast hind feet with Spinning Saucers. An armada of Minifos show up to provide assistance but these are dispatch quickly by the Team, with Hikaru blasting Dai's forward feet with Marine Missiles. Then Grendizer connects with the Driller Spazer, the two making a dash straight to Dai, slicing its right wing, Koji decapitates the monster with Double cutter, while Maria rips its left wing off with Marine Cutter; Duke and Koji finish the Beast off mid air with a Space Thunder/Cyclone Beam combo.

After the battle, the group realized what had happened, suggest to stop the launch, but by then is too late, the Monitor Satellite is destroy with a missile. Despite this, Umon knows Shubyler, and saw him smoking his pipe with the right hand, when he is left handed, and when in agitation, Shubyler would take his glasses off. Finally, the person in the Convention had knowledge of the Beast without not having seeing it.

Concern, Umon and the group run to Shubyler's residence, where they find him and Elza gag and tied; after freeing them, Elza explain the situation to them, and realized Vega's intent. At the Underwater Base, the King congratulates Zuril on his mission. Meanwhile, on their way to Japan, Duke suggest to prepare a second Monitor Satellite.