Ullu is primarily white, with gray patterns along her chest, wings and head. She has blue eyes and a small, dark gray beak, and two white feathers on each side of her head. Her talons are dark gray with black talons.
Ullu is shown to be a helpful owl, warning the Night Pride whenever there is a potential threat to the Tree of Life.
Ullu spots the Lion Guard from her tree branch and suspects that they are a threat, so she goes warns the Night Pride. She brought the Night Pride to the pass, but there is now a rockslide, Rani thanked her for warning them and then she flew off.
Ullu overhears Makcuha's Army and goes to reports this to Rani and the Night Pride. Meanwhile, the rest of the Guard find Kion and tell him about Ullu fetching Rani. The next morning, Ullu arrives at Dirisha tells Nirmala that Rani needs her and the predators are back.
Ullu overhears "Granny Gimterbong" and that the predators were chasing her and unaware that she is pretending to be in peril, Ullu gets the Night Pride to the pass, where they rescue her from the predators. Later at sunrise, Ullu hears Granny Gimterbong cries for help from Ciso River, Rani then tells her to pass along a message to the Lion Guard. Ullu found and wakes them, informing them Granny Ginterbong is being attacked at the icy river, but Ono realizes Granny is working with Makucha, Kion tells Ullu to go warn the Night Pride that Granny is a decoy. Ullu soon arrives with Kion's warning about the ginterbong to the Night Pride.
Uluu spots Makucha's Army coming towards the Tree of Life, so she goes to warn the Night Pride. After Mama Binterong orders Sun's prickle to watch her during the biggest attack yet, she escapes by freaking them out with one of her owl-only abilities.
Ullu tells Rani that she just spotted a cheetah coming through the pass. It was Azaad helping Janja and Jasiri find their way to the Tree of Life to warn the Lion Guard that Zira has returned to the Pride Lands with her two of her fully grown spawn.