Lance's Dragonite (anime)

Lance's Dragonite is Lance's signature Pokémon.

Johto
Dragonite first appeared with Lance where it helped defeat Team Rocket and quell the Red Gyarados's fury. It fought against the Red Gyarados, using powerful moves to defeat the Red Gyarados, allowing Lance to catch it.

Hoenn
Lance and Dragonite reappeared in Hoenn, where they battled Groudon and Kyogre, calming them down after Team Aqua and Magma summoned them.

Yellow arc
Dragonite appeared with Lance during the Elite Four gathering at Cerise Island. Afterwards, it emrged from the ground with Gyarados, for Lance sent it there to cause tremors. Like Lance's other Pokémon, Dragonite was loyal and did not want to disobey his trainer nor his ideals.