Mjomba is a sturdily built aardwolf with striped gray fur and bushy unibrow. He has three stripes on each foreleg, a V-shaped marking on his chesk, and a mask of darker gray fur around his face. His pupils are black, and his sclerae are yellow. He has long scruffy fur on tops of his ears and his cheeks. He has a black tail, a pale lavender underbelly, and deep gray paws.
Like all of the aardwolves, he is described to be shy. He loves termites and does not like being deprived of them. He is grateful to those who help him. He appears to be rather grumpy, impatient, and short-tempered.
Mjomba and the rest of the aardwolf pack are driven out of the Pride Lands by Kion's Roar of the Elders. Later on, the Lion Guard follows them into the Outlands, and Ogopa reports to the pack as they hide behind some rocks, declaring that she saw them. Mjomba irritably asks why they would be after them, as they already chased the aardwolves out of the Pride Lands into the "termite-forsaken" Outlands. The aardwolves then move behind another rock. While spying on the Guard, Mjomba spots a bug. He happily dives after it. After the Lion Guard pases by, pursuing the rest of the pack, he emerges. Noticing the Guard running by, he notes that is really is them and asks why none of the aardwolves said anything.
Mjomba runs towards a cliff, but is chased by Bunga. The honey badger pins him to the ground. He cries out as he hits the ground on the edge of the precipice, and, struggling to free himself, demands that Bunga gets off of him. He asks what Bunga thinks he is doing, and Bunga points out that he is saving Mjomba's life. Mjomba rolls over, notices the drop ahead of him, and thanks Bunga. He asks what the Guard wants now, considering that they already kicked the pack out of the Pride Lands. He proceeds to question where the Guard wants them to go, and Kion responds that he wants them back in the Pride Lands. Mjomba queries whether it would have been easier for the Guard to not kick them out in the first place.
Kion explains that it was a mistake, and that the Lion Guard thought they were hyenas. Affronted, Mjomba asks if he looks like a hyena to them. The Guard replies saying that he does. Kion continues, telling Mjomba that they still need the rest of his pack. Uncertain, Mjomba asks what is in it for him, and, after being promised plenty of termites, he happily agrees to help after licking his lips. In his eagerness, he runs ahead of the Guard.
After discovering where the aardwolves are, Kion asks him to enter the rock den and inform the pack that is Guard is not a threat. Mjomba agrees, and Kion tells him what to do so they can go back to the Pride Lands. Mjomba blissfully adds, "Then I can eat!". Muttering about unlimited termites, he goes inside. Calling out a greeting, he asks if there are any aardwolves at home. The pack is there, along with Reirei and Goigoi. Haya approaches and asks if it is him, to which he responds that it is, and that he has news. To their surprise, he explains that the Lion Guard are the "good guys" and that they saved him. Ogopa suspects a trick, inquiring if they are behind him. He denies this and tells them that the Guard thought they were hyenas and that they are wanted back in the termite-crawling Pride Lands. He exclaims that they are needed to eat them all, and declares, "Let's go!"
Reirei blocks their way, commenting that she thought they were staying for dinner. He asks if she has any termites, and she replies that none of them will be leaving hungry. Adding that none of them are leaving at all, she has Goigoi block the way out, causing the pack to gasp in shock. The aardwolves back up as the jackals advance before pouncing. They move out of the way, but are chased. However, just as Reirei prepares to sink her teeth into Mjomba's back, the Lion Guard enters. Mjomba opens his eyes and leaps away after Kion attacks Reirei. Fuli leads the aardwolves out of the den, and they escape. Safe, Mjomba remarks that he could use a termite and asks to go home and eat. Kion obliges, and they return to the Pride Lands.
The aardwolves later send Bunga a thank-you gift of termites.