• English / United States: Grusha's Altaria
• Japanese / Japan: グルーシャのチルタリス
• Japanese (Romanized) / Japan: Grusha no Tyltalis
• Japanese (TL) / Japan: Grusha's Tyltalis

Grusha's Altaria is Grusha's main partner Pokémon. It is able to Terastallize into an Ice Tera Type.

Terastal Practical Application Test VS Liko

Liko's Floragato used Magical Leaf in Grusha's Cetitan mouth making it hard to use moves, so Grusha recalled it and swapped it with Grusha's Altaria. Altaria had the type advantage and the skill advantage, so when it came down to them both Terastallizing, Altaria was still more powerful and it defeated Floragato, making Liko lose the battle.