Mzingo's feathers are colored a very dark blue, paler on undersides of his wings and tail. His wings are three shades of blue, starting out dark blue, changing to a slightly lighter shade along the center, and finally becoming a pale gray-blue. He has a thick white ruff of feathers around his neck that extends down past his wings. He has black eyes, with purple lower lids and deep pink upper lids. His neck and head are both dull pink, with darker skin around his face. A smooth, triangular blue crest rises from the back of his head, forming a recurved spike. Three smaller spikes of this crest reach down towards his black eyebrows. His long, wide beak is bicolored; it is mostly a dull yellowish gold, but the curved part of his upper beak is red-orange. His legs are the same yellow as much of his beak, ended in sharp black talons.
Mzingo is opportunistic and sneaky. He shares a desire with the hyenas to eat at his leisure, no matter the effect on the Circle of Life, and cares nothing for the other animals of the Pride Lands. He has a dry and sarcastic demeanor, and he speaks with a sense of eloquence. Despite how devious Mzingo is, he is quite dignified. He is more sophisticated than his hyena allies, as he and his committee work in a parliament, with almost every decision being presented as a motion to be voted on. However, he is also willing to dismiss parliamentary procedure if there is a good opportunity.
Mzingo overhears Kion talking to Bunga about a new Lion Guard, and since a new Guard would make his own life much harder, he relays the news on to Janja, the leader of the hyenas. Although initially believing that Mzingo was looking for food, Janja becomes concerned when he hears the full story, remembering what the Lion Guard once stood for before Scar took advantage of his powers. He concocts a scheme to take down as many animals as he and the other Outlanders can before the new Lion Guard is formed, starting that very night, and Mzingo joins in the song briefly.
When Kiara and Tiifu arrive at the gazelles' grazing grounds, they soon become suspicious as Mzingo looms overhead. Kiara tells Tiifu to get her father whilst she keeps an eye on Mzingo and the hyenas. It doesn't take long before the Lion Guard arrive on the scene, where Ono notices that Mzingo is telling the hyenas which one to attack next, admitting that it was pretty smart (albeit devious). When the Guard ambush Mzingo and the hyenas, Mzingo is defeated by Ono, who knocks him into a bush.
Mzingo overhears Simba, Nala and Zazu speak about leaving Kiara as queen as they make their way over to Kilio Valley. He decides to investigate, and later notices the Lion Guard performing a task for her. He's quick to notice that Kion is annoyed at this, and soon returns to the Outlands.
He informs Janja of the new queen, and the sibling squabbling between her and her brother. This gives Janja a plan, and tells Mzingo to give a message to the new queen.
Mzingo returns to Pride Rock, and begins to flatter Kiara. He offers her a peace proposal, direct from Janja, telling her that Janja has always wanted peace, and blaming Kion and the Guard's stubborn personality for not asking sooner. Kiara asks why he couldn't come over himself, though the vulture reminds her that Janja is not welcome in the Pride Lands, and that she must meet him in the Outlands, in neutral territory. Kiara tells him that she'll think about it, and Mzingo leaves, telling her 'that's all we ask'.
Mzingo is seen speaking with the other vultures of the Outlands in a parliamentary meeting atop a withered tree. Another vulture, who Mzingo identifies as Mwoga, apologizes for being late as he flies in. Mzingo then confirms with the other vultures whether everyone is okay with allowing him to speak. He asks the reason for his tardiness, and Mwoga explains that Ono has a wounded eye. Mzingo considers a sub-committee to deal with the issue, to which it is agreed. As they speak, Janja listens below them intently.
Mzingo and his committee are seen perched in a tree. Mzingo calls them to order and decides to sing their parliamentary anthem. Once they are finished, a member of Mzingo's committee, Mwoga, spots Fuli lying on the ground, exhausted. Mzingo notes that she must not know her limits. He explains to his committee that Fuli appears to have pushed herself to her limits and drained herself of energy, meaning that she is currently unable to defend herself. Mwoga suggests that they form a subcommittee to focus on the situation, but Mzingo decides to not abide by the usual parliamentary procedures and to simply attack Fuli.
Mzingo and his committee descend around Fuli. She attempts to warn them away, but Mzingo points out that she does not have enough energy to attack them. Though Mwoga is doubtful that Fuli is entirely unable to fight back, Mzingo tells Fuli that she would have pounced if she had any energy, and votes to attack from all sides. His committee agrees, and they converge on Fuli, Mzingo assuring Fuli that it will "all be over soon". However, just as Mzingo begins to attack, Kion intervenes, tackling Mzingo and knocking him away from Fuli. Mzingo orders his committee to reconvene, and they are blasted away by the force of Kion's Roar of the Elders.
Mzingo, Mwoga, and a third member of the committee are circling in the sky. It is soon revealed what their sight is set on, as they begin to chase Baby Baboon. When the time is right, Mzingo suggests that they forgo debate and dive into business. However, the Lion Guard arrives having noticed them in the near distance and Mzingo crashes into Beshte as the hippo blocks him from taking his meal. Mzingo then backs away, ordering the others to yield to the Guard, and flies out of sight.
The trio are later circling once more, with Mzingo certain that he saw the baby baboon somewhere, and votes that they keep looking. The others agree, and they fly over the land until they hear a noise that Mzingo believes sounds like a young baboon. He decides to investigate, and when his companions agree, they descend onto a tree. Mzingo spots some grass shifting, and chuckles, crooning for the baboon to come out. Fuli emerges, to Mzingo's evident disappointment, and he mutters a greeting. Mzingo asks her what became of Baby Baboon, whom he claims they were trying to help. Fuli is skeptical, and Mzingo insists that the baboon was lost and that the vultures were attempting to guide him home. Fuli feels that he's probably already home now, and informs them that she's on a hunt. Mzingo curiously asks what she's hunting, only to be told that he's looking plump. Mzingo sputters a response and adjourns the meeting.
The three vultures eventually locate Baby Baboon at Mapango Cliffs, and Mzingo passes a motion to engage with their lunch, diving at the baboon and ordering the others to attack. Fuli orders them away, but Mzingo declares that it's useless, and she is unable to climb the cliffs faster than they can fly. However, a fruit strikes him in the face, thrown by the baboon troop. Mzingo commands his fellows to get the baby as he takes on Fuli, and dives at the cheetah. She lashes out at him, holding him at bay, but soon slips and falls. As Mzingo prepares to strike, another fruit hits him, then a second, knocking him out of the air. His talons snag on a dead branch, and he frees himself, diving upwards to attack once more. Fuli pounces on him and pins him, demanding that he orders his parliament away. Mzingo complies, denying Mwoga's suggestion to put it to a vote, and flees into the sky.
Mzingo and part of his Committee notice an animal who has strayed in the Outlands and begin circling around the fatigued calf. Mzingo and his Committee prepare to attack, but Bunga and Fuli frighten him away by using a hollow log which amplifies Bunga's voice, making him sound like a ferocious creature.