Finding Croconaw
Croconaw can be found in Phenac City as a Shadow Pokémon in the "Pokémon Colosseum" game for Nintendo's GameCube. Go to the Snagem Hideout in Phenac City to find Croconaw, as well as the other Shadow Pokémon Bayleef and Quilava.
In the Snagem Hideout, you will find men wearing suits of all one color. The man wearing the blue suit has Croconaw.
Catching Croconaw
To battle the man in the blue suit and catch Croconaw, you must send out Espeon as your Pokémon. Attack with Confusion. You will probably have to attack many times to weaken Croconaw. Capture Croconaw with the strongest Pokéball you have.
What to Do if You Miss Catching Croconaw
If you defeat Croconaw in battle but do not capture him, or if you lose the battle, simply leave the area and return. The man in blue will still want to battle, giving you another chance to catch Croconaw.