Ash caught a mischievous Snorunt whilst traveling through Hoenn. This Snorunt had trouble controlling its Ice Beam attack. Snorunt was used during Ash's battle with Juan but was defeated by Seaking's Hyper Beam. While May was competing in the Grand Festival, Snorunt evolved into Glalie in order to fend off Team Rocket and mastered Ice Beam as soon as it evolved.
Although it was newly evolved when Ash entered the Hoenn League Ash used it in a number of battles where it managed to hold its own successfully, first defeating a Charizard used by Clark with a powerful spinning headbutt. Later he used Glalie against Morrison's Metang, and after a hard battle, pulled it off and won the match for Ash. During Ash's Top 8 match, Glalie battled Tyson's Sceptile, an incredibly powerful Pokémon who, like Glalie, had won multiple decicive victories for Tyson. However they both lost after using their first moves, as their Solar Beam & Ice Beam clashed and knocked them both out.
After the league was over he decided to give it a break at Oak's Laboratory. Ash was going to use Glalie against Conway in the Sinnoh League but made a quick change as Conway saw Ash was going to use Glalie.