From Bulbapedia, the community-driven Pokémon encyclopedia.
The Dragon Clan Elder (Japanese: ちょうろうさま Elder) is the leader of a secret society that worships Dragon-type Pokémon. He lives in the Dragon's Den located north of Blackthorn City.
In the games
The Elder appears in Pokémon Crystal, HeartGold, and SoulSilver Versions. When spoken with for the first time, he will give the player a quiz about caring for their Pokémon. After the quiz he will reward the player with a Dratini: but if all questions are answered correctly, then the Dratini will know the move ExtremeSpeed. This high-priority move cannot be learned by Dratini in any other way. It is level 15.
Two of the Elder's descendants are Lance and Clair. Both of these Trainers are capable battlers who also use the Dragon-type. Sometimes, they will come to the cave and visit their relative.
In the manga
In the Pokémon Adventures manga
The Dragon Clan Elder makes a visit with Clair in order to train her to be stronger.