The Leader first appears when he hears Niko telling Julius that he is going to Antler Hill to practice flying, to which the Leader forbids him to as wolves are there and that's why they don't leave Home Valley.
He is later seen with Oona and Grandpa when his daughter Saga along Niko come over to them, saying that they saw wolves. Though Niko says that he and Saga lost the wolves, one of the wolves named Smiley appears and runs at the herd. The Leader sends the herd away while he knocks Smiley to the ground before leaving to catch up with the herd. Smiley pursues the Leader, but ends up being trapped under snow when the Leader knocks down a snow covered tree, before falling to the ground.
Later, he is seen with the herd lying on the ground with Saga by his side whilst Grandpa berates Niko for leading Smiley to the herd and causing the Leader to get hurt. Oona stands up to her father and says that Niko is just a boy and that the wolves will return and that there will be many, which the Leader agrees before going with the herd elsewhere. Whilst journeying to a new home, he forbids Saga to play with Niko again, saying that next time he might bring death to them all.
After noticing that Niko is not with the herd, Oona say that they have to go back and find him, but the Leader tells her that they must continue or the wolves will track them down and when declares that she's not leaving without her son, the Leader tells her that no one leaves the herd, worried she might cause the wolves to come to them, so Julius says he will find Niko.
The Leader later appears with the herd when Julius comes to them to tell them that Niko can fly and has joined the Flying Forces, but he and the herd don't believe him and are angry at him for not bringing Niko back. Just then, Niko arrives with Wilma and reunites with Oona while the Leader and Grandpa look on happily. He also witnesses Niko turn down an offer by his father Prancer to join the Flying Forces to remain in the herd, but promises to visit after Christmas. The Leader is last seen when he and the herd are led by Niko and Julius to a new home with plenty of food and water.
- For unknown reasons, neither the Leader or Grandpa reappear in The Flight Before Christmas's sequel Little Brother Big Trouble: A Christmas Adventure, despite being major characters.