The Super Rod is an item that can be used to catch Pokémon that are found in water, like Squirtle, Goldeen, and Golduck. The Pokémon that can be caught depend on the biome that the player is in. It is not legitimately obtainable yet, and must be spawned in.
Possible Catches
Goldeen and Magikarp appear regardless of the biome the player is in.