Grovyle is the evolved form of Treecko, a starter Pokémon in Pokémon Ruby, Sapphire, and Emerald. These games are different from HeartGold and SoulSilver, so the starter Pokémon you choose in those games won't be available in HeartGold and SoulSilver.
How to Get a Treecko in HeartGold and SoulSilver:
* Trade: You can obtain a Treecko by trading with someone who has a copy of Pokémon Ruby, Sapphire, or Emerald.
* Events: There were some special events in the past where players could obtain Treecko in HeartGold and SoulSilver. However, these events are no longer available.
If you're looking for a Grass-type Pokémon in HeartGold and SoulSilver, consider these options:
* Bayleef: Evolve a Chikorita (found in Ilex Forest)
* Sceptile: Trade for a Treecko from another game
* Shroomish: Found in the National Park
* Seedot: Found in the National Park
* Grovyle: Trade for a Treecko and then evolve it.