Articuno (mystery dungeon)

It was the boss of Frosty Forest

Plot
When taiya & volty enters the Frosty Forest in order to escape from the Pokémon who pursued them, Articuno sensed the change of the forest, and decided to stop them from going farther It talked as a voice from nowhere about the temperature rise and stopping the distrubing of the intruders after taiya & volty reaches 5F of Frosty Forest.

After reaching 5F of Frosty Grotto, Articuno suddenly lands in front of taiya & volty like Moltres

he introduces himself as the Warder of Ice, and blamed taiya for upsetting the nature’s balance

volty begged Articuno for letting them through, but Articuno doesn’t agree and starts to fight them