In his youth, he was present at the Battle of the Great Sky Whale. He pretended to be a labourer from the Great Sky Whale, using the assumed name of "Pen". He fed Ice Fox, captain of the Cloudbreaker, information on the Leagues' movements in order to lead the sky pirates into a trap. His scarf was cut up and distributed among the sky pirate armada so that ratbirds could use the scent to locate the massive slave ship. Wind Jackal realized Ulbus' treachery when he remembered fighting him and his father aboard a sky raft above the Mire.
During the events of Clash of the Sky Galleons, Ulbus brought Thaw Daggerslash—who was masquerading as Turbot Smeal—to the Palace of the Leagues in Undertown. He presented Thaw to his father, High Leaguesmaster Ruptus Pentephraxis, before the Leagues' fleet set sail to battle the sky pirates.
Though as ruthless as his father, Ulbus never had Ruptus's tactical skills; thus, he never rose to the rank of High Leaguesmaster. Nevertheless, Ulbus still became a league captain, and gained a reputation for brutality in battles with sky pirates. Ulbus fought Cloud Wolf on multiple occasions. In one such battle, he snuck up on Stope Boltjaw and destroyed his jaw with a hunting axe.
When Ulbus realized that his son, Cowlquape, wasn't cut out to be a leaguesman, he bought Cowlquape a position in Sanctaphrax. Later on, he was killed when the rudder-wheel of the Edgedancer came crashing through the Leagues' Chamber and flattened him, along with Simenon Xintax and Farquhar Armwright.
Ulbus was known to be cunning, outsmarting the sky pirates and surprising Stope with an axe blow. He was also known to be brutal and cruel. This was especially true for his treatment towards his son, Cowlquape, who he had a tendency to beat from time to time.
- ↑ Cloud Wolf, Chapter 1: Wilderness Lair
- ↑ Cloud Wolf, Chapter 3: Attack!
- ↑ Cloud Wolf, Chapter 2: Ratbirds and Turbulent-Fog
- ↑ 4.0 4.1 Cloud Wolf, Chapter 4: The Sky Battle
- ↑ 5.0 5.1 5.2 Clash of the Sky Galleons, Chapter 19: Clash of the Sky Galleons
- ↑ 6.0 6.1 Stormchaser, Chapter 11: The Eye of the Storm
- ↑ Midnight Over Sanctaphrax, Chapter 3: The Loftus Observatory
- ↑ Midnight Over Sanctaphrax, Chapter 17: The Deepwoods' Dark Heart