A/N – This fic is mostly inspired by the idea that Momo is Gyasto's reincarnation which fills me with feels like you wouldn't believe.
Disclaimer: I don't own the characters and I'm not using them for profit.
It was three days after Aang began training the first airbender born in 119 years that Momo died. The family was not too surprised as they had witnessed his increased lethargy and the gradual dimming of his round green eyes. He lived an inordinately long time for a lemur according to Aang. Despite his passing being no surprise, the loss was deeply felt by Aang, Katara, and their children.
Katara and Aang had managed to console three weepy children and usher them into bed for the night before turning in themselves. He remained fairly stoic in front of Kya, Bumi, Tenzin, only allowing a few of his own tears fall quietly. But now that he was alone with his wife in their bed, Aang had buried his head in her lap and cried with an intensity that he was not expecting. Katara could only lovingly stroke the azure tattoos on his scalp while crying with him.
Momo had been there from the start of their adventure together and neither was quite ready for the heavy weight his loss has placed on their hearts. He was one of the last links that Aang had to his extinct culture. He had been more than a pet or a companion. He too shaped the outcome of the 100 Year War. Momo was an incarnate reminder of his morals, beliefs, and philosophies to perch on one shoulder when Aang needed to draw from wisdom he felt he didn't have. One more than one occasion, Aang would look at the lemur and imagine what his mentors and guardians would advise him to do. And now he had given Aang and his wife the opportunity to teach their children about death, loss, and how those things create a beauty in life. Ultimately, Momo had been the one to facilitate Aang accepting the cruel truth that there we no more airbenders, that Gyasto, as he knew him, was truly gone.
Katara couldn't pretend to understand what his death would mean for her husband or how he could possibly be feeling right now. But she grieved as he did. Katara had always been fond of him, finding his mischievous and playful nature not very much unlike Aang's. Her affections for the lemur increased tenfold during her pregnancy with Tenzin. Before she had even noticed the subtle changes in her body, she had noticed Momo's sudden clinginess. Usually he was inseparable from Aang but on days when she was fatigued and queasy, Momo opted to stay curled up in bed with her. His eyes followed her everywhere she went and it was almost disconcerting. He knew something that she did not and it had taken Katara nearly into her second trimester to figure out that Momo had known of her pregnancy long before she did.
That wouldn't be the last time that keen insight caused Momo's strange behavior. Momo had chittered and chattered at her for two days before she finally went into labor after 41 weeks of pregnancy. Three hours before she was certain the baby was coming, Katara had been trying to ease the discomfort of late pregnancy by soaking in a tub when the lemur had all but jumped in with her, yanking at her hair and screeching loudly.
Katara found herself frustrated but very warmed by the fact that she often had to shoo Momo away from Tenzin. She would find him curled up with the baby while he napped in his bassinet, leaving white and black fur everywhere. During Tenzin's toddler, he would often bring the boy still buzzing insects and whatever fruit he could find when Aang and Katara's backs were turned. Tenzin more often than not quickly consumed these gifts. Even when the tail-pulling and fur-grabbing began, Momo stayed just out of arm's reach.
Katara was so lost in her own thoughts that she didn't register the softening of her husband's cries into gradual silence.
"Katara, when did we know that Tenzin was an airbender?" he asked softly.
"I don't know, Sweetie. It seems like we just kind of assumed…like we always knew. We knew before we ever saw him bend air."
Earlier that day, just as Aang and Tenzin had finished their third training session. Momo sat in the courtyard nearby and Tenzin had commented with concern, "Daddy, Momo looks tired."
It didn't take a visit from one of Aang's past lives or forceful gale of wind from a sneeze for Katara and Aang to know that Tenzin was an airbender. Without speaking words, Momo had subtly planted that knowledge with his erratic behavior and strange fascination with their third born. He lived just long enough to see that Tenzin's training start correctly and that Aang truly no longer needed him. They had never quite pieced this all together until now and Aang's tears began anew.