Growlithe made his debut in To Catch A Growlithe where Lillie was determined to befriend him. Team Rocket captured him in a net, but Lillie risked her life to save him from the villains almost getting killed. Growlithe saw the love Lillie had for him and sent Team Rocket blasting off with a ember attack. Growlithe asked to join Lillie on her Pokemon journey and she accepted catching him as her first Pokemon she ever caught. In another episode, Growlithe and the rest of Lillie's Pokemon were captured by Team Rocket who demanded Lillie. But Gabe and her friends rescued Lillie, Growlithe, and the rest of Lillie's Pokemon. In Lillie & Growlithe: A New Bond, after recieving Rockruff as her starter Pokemon from Professor Kuikui, Lillie decides to go on a short adventure by herself with her Pokemon to get to know Growlithe better. Team Rocket followed Lillie at a distance determined to capture Growlithe. Team Rocket trapped Growlithe, Lillie ordered them to let him go. But Jessie told her that Growlithe was a gift for their boss and told her goodbye and attempted to escape with him. Lillie pulled out her Poke Balls, but Meowth used the grabber to grab them with Jessie exclaiming that the Pokemon in the Poke Balls would make a bonus gift. This enraged Lillie who told them angrily that nobody messed with her Pokemon. Gabe and her friends who had followed Lillie helped her get Growlithe and her Poke Balls back and Gabe sent Team Rocket blasting off.
Like any normal Growlithe, Growlithe is very protective of his trainer and would go to desperate measures to protect her. This trait confirmed him to be male.