Togepi

  Togepi is a PokéGod. It is a real Pokémon, but before Gold and Silver came out, it was a PokéGod.

Location
There are a few methods to catch Togepi:

Walk left to right twenty times on the shore of Fuchsia City. Then go to the Safari Zone. Togepi can be found.

Catch all 150 Pokémon without using GameShark and go to the Elite Four. Defeat Lorelei, Bruno and Agatha. Save your game and turn off the power before fighting Lance and your Rival. Without turning off the game, go to your house in Pallet Town to find you mom standing on your bed in fear of the Pokémon running around your room. She will then allow you to take the Togepi.