Here's why:
* Totodile is a Johto starter Pokémon. Pokémon XD takes place in the Orre region, which is a completely separate region from Johto.
* The game's roster is limited to Pokémon found in the Orre region. This means you won't find any Pokémon from other regions, including Johto starters.
While you can't get Totodile in the game, there are still many other exciting Pokémon to catch and train!