Mahkah was found in the woods surrounding the Western Air Temple. Anju found this little guy when he was roughly 5 months old. His back right leg was broken and he looked like he was close to death. Meaning that his mother had probably abandoned him. So Anju brought him back to the Air Temple and nursed him back to health.
She learned that animals often trust the ones that have the food, so she learned that if she was the one to always feed him, Mahkah would learn to trust her and really only her.
When she tired to let him go, he came back to her and stayed by her side. He often goes out to hunt, but always comes back.
When she traveled to Republic City, Anju and Mahkah became best friends. Because Anju is and earth bender and Mahkah is from the wilderness, they got along just fine. Anju could take care of Mahkah and Mahkah could look after Anju whilst she slept.