Ash's Corphish is the third Pokémon that Ash caught in Hoenn. It's Japanese voice actor is Katsuyuki Konish, and in English it is voiced by Maddie Blaustein (4Kids) and Bill Rogers (TPCi).
Ash first saw a different Corphish in the episode, "Which Wurmple is Which?", while fishing. However, Corphish ran away. In the episode, "Gone Corphishin' ", a strange figure was moving underground. Brock had a plan to reveal the figure and the plan worked. Ash realized that he caught a Corphish before on the fishing rod. Ash wanted to capture it so he used Pikachu. Pikachu was no match for Corphish despite the type advantage. Treecko was sent out instead. Using the method that Ash and his Pokémon practiced, Treecko was able to overcome Corphish's strength and thus, Ash was able to catch it.