The Grand Duke of Owls is a powerful owl sorcerer who briefly fights in the Disney vs. Non-Disney Villains war against Doctor Facilier.
He was the main villain of the Don Bluth animated film Rock-a-Doodle.
Disney Vs Non Disney Villains
Eris, seeing the Grand Duke of Owls as a threat to her plan, sends her minion, Doctor Facilier, to asassinate him. Facilier confronts the Duke in his tree. Rather than silently surrender, the Duke grows to enormous size and creates a tornado to try and kill Facilier. Unfortunately for him, Facilier manages to reverse the Duke's tornado, shrinking him to a smaller size. In this state, he is presumably killed by Facilier.
Non Disney Villains Tournament
The Grand Duke of Owls is part of a considerable faction of evil dark beings, including Nightmare Moon, Samhain, and Dracula himself, known as the Legion of Darkness. An undeniably weaker member of the faction, the Grand Duke of Owls is relatively content with his position, though he desperately wants to keep it.
With the rise of Myotismon in the faction, the Grand Duke finds his place in the alliance all the more threatened. He thus decides to defend his position by taking on the most available opponent. That turns out to be Septimus, an elf who accidentally teleports into the Grand Duke's lair. The elf gets a slight advantage after knocking one of the Grand Duke's minions into him, but the Grand Duke recovers quickly. The two fire all their magics at each other, and the Grand Duke has more energy to offer. His magical breath reduces Septimus to ash.
Myotismon has the Grand Duke track down an amulet in the possession of Professor Screweyes, who recently killed Samhain. The Grand Duke is initially frightened by Screweyes's various monsters, but he musters up the courage to destroy them with his magic breath. The Grand Duke is less prepared to take on the Kralahome, a surprise player who blasts him out of Screweyes's circus with a firework.
After his defeat, the Grand Duke realizes the fragility of his position in the Legion of Darkness. He thus decides to go renegade, resurrecting his fallen comrade, Nightmare Moon. Devimon, Myotismon's right-hand man, discovers the two, forcing them to fight back. The Grand Duke blows some of his powerful breath at Devimon, but the Digimon effortlessly blocks the attack. Fortunately for the Grand Duke, Nightmare Moon is able to blow Devimon away.