Muhimu is a large, stocky zebra. She is white with black stripes all over, and has blue eyes. She has a diamond-like marking leading down to the middle of her snout, the bottom of which is black. Both ears are pure white with pink inner ears. She also has black hooves and a black tail tuft. Her mane is straight, save for a few strands of black hair which hang loosely at the front near two large black eyebrows.
Muhimu is first seen as very argumentative, cantankerous, hot-tempered, and irritable, with little to no faith in the Lion Guard's ability to lead her herd. She is also extremely oversensitive and impatient, as is evident by her rushing into danger when she noticed her new grazing grounds. She also able to show humility when necessary, sticking up for Kion when others start to lose faith. Towards the end of the journey, she becomes a much calmer entity, and has learned to trust the Lion Guard, as well as Swala and her herd. Muhimu has been described as a strong character. She even trusts Bunga to look after her son Hamu.
Being the leader of a small zebra herd that shared the grazing grounds with a herd of gazelles led by Swala, the two leaders are first seen fighting due to a lack of grass for them to eat. When the Guard arrive, Muhimu continues fighting, sitting on Bunga by accident. Kion roars for everyone's attention, and although he explains that the Pride Lands are for everyone, Muhimu and Swala explain that the reason they're fighting is because there is only one patch of grass left for them to share between their herds.
Later, as Bunga is racing around the Pride Lands with the news of a migration to Mbali Fields, he bumps into Muhimu who denies ever sitting on him during the fight, calling him a mongoose instead of a honey badger. She explains that she needs to reach the new grazing grounds as soon as possible.
Soon, Kion announces to the two herds that he and the Guard will be leading them to Mbali Fields. Muhimu's herd and Swala's herd are satisfied, and cheer for Kion. As he and the Guard keep everyone in check, the Trail to Hope begins, with everyone looking out for each other as they move across the Pride Lands.
Eventually, they wind up in a canyon. By this time, both of the herds are hungry and show signs of fatigue. The herds soon see Mbali Fields, and Muhimu cannot wait any longer. She and her herd rushes ahead down the canyon, which causes Swala and her herd to react competitively as they charge after them. The Lion Guard attempt to stop them, but a large pile of rocks plummets into the canyon, blocking the path to Mbali Fields. The rocks keep falling though, and almost hit Muhimu. Bunga leaps onto her just in time to rescue her from being hit by more rocks, and she is surprised that Bunga managed to rescue her and sitting on her buttocks.
As they make their way across a new path, a storm erupts. Suddenly, a huge gush of water comes flooding through. Kion realises that it's a flash flood, and orders everyone to reach higher ground. Ono is tasked with leading them higher, as the herds make a dash for a nearby slope rising upwards, though Muhimu is amongst those who does not make it in time. Bunga notices that Muhimu is floating away with the current. He leaps in and grabs her, though Muhimu has her doubts that he can save her, becoming a little aggressive as Bunga asks her to help him save her. Eventually, she starts paddling with Bunga, and he is able to help her reach safe grounds. She is grateful for his help, and notes that it's the second time he has saved her during the same day. She thanks him for his help, and finally admits that she did, in fact sit on him (to which Bunga replies that he knew that already).
Later, the herds express their annoyance with Kion as their leader, even after he returns with confidence. Muhimu speaks up, telling everyone that it was her fault for starting the stampede, that it she had not, they would not have had to change course. She promises to make things easier from then on, which Kion is appreciative of. He once again promises that he'll get everyone there safe and sound, and the herds show their support. Meanwhile, Muhimu asks Bunga if he'll keep her safe, to which he agrees.
The herds enter the Outlands, but soon after, Muhimu enters labor. Kion sends Beshte, Fuli and Ono ahead and tells them to keep leading the herds whilst he and Bunga stay behind to help her give birth. Some of the zebras stay behind, as does Swala, to help her. Soon Muhimu gives birth to a son. However, he lets loose a loud bray, which draws Janja, Cheezi and Chungu's attention. However, the three hyenas soon arrive and slide down the ridge, causing most of the zebras to scatter. After Muhimu orders them to, the zebras compose themselves, rushing back to Muhimu and her foal, defending them along with Kion, Bunga and Swala. After Janja manages to break away from Kion, he approaches the zebras, who pull back a little, though Muhimu's son kicks Janja in the face, throwing him away at the same time Bunga and Kion finish with Cheezi and Chungu. Muhimu is amazed that her son saved her life, and Bunga compliments him.
The remaining animals finally make it to Mbali Fields, with everyone happy at last.
Muhimu appears with her son and herd when they are suddenly attacked by Reirei's Pack. She tells Hamu to panic and run, although she speeds up too much for him to handle and the pair are separated. Once the Guard deal with the jackals, she becomes worried when she cannot locate Hamu, but is relieved to see him with Bunga. After the ordeal, Muhimu still is uneasy about what happened, so Beshte suggests taking a break at the Watering Hole. But she worries about her son. When she sees how well Hamu and Bunga get along, she asks the honey badger if her son could stay with him, and Bunga agrees.
She arrives at the Watering Hole and, after seeing how calm she is, Twiga asks where Hamu is and she tells Twiga that her son is with Bunga, leaving other parents to wonder if he might babysit their children as well. Once the other children have been dropped off and during her time relaxing, Muhimu asks Twiga to try the grass beside her to which she does. She asks Twiga if they should pick up their kids but Twiga says that their kids are having fun with Bunga, unaware that Reirei is listening in on their conversation.
At sunset, Muhimu shows up with the other moms to pick up their kids. She then hears that her son fought off the jackals which shocks her at first, until Hamu explains how Bunga taught them to teke, ruka and teleza. Impressed by the fact that Bunga taught the kids how to defend themselves she declares Bunga to be the best babysitter ever.