Electrode

Electrode (マルマイン Marumine) is an -Type Pokémon. It is the evolved form of Voltorb. It is known to drift on winds if it is bloated to bursting with stored electricity. It's nicked named the Exploding Pokémon. Like Voltorb, Electrode is very easily mistaken for a Poké Ball.

Locations
To get one in Red and blue, it can be found in the Power Plant or Cerulean Cave.

To get one in Yellow, it can be found in the Power Plant.

To get one in Gold, Silver, or Crystal, it can be found the Team Rocket base in Mahogony Town or evolve a Voltorb.

To get one in Ruby, Sapphire, or Emerald, it can be found in the New Mauville Basement.

To get one in FireRed and LeafGreen, it can be found in Cerulean Cave.

To get one in Colosseum, it has to be traded from Ruby, Sapphire, Emerald, FireRed, LeafGreen, and XD.

To get on in XD, Diamond, Pearl, or Platinum, it has to be evolved from a Voltorb.

In other games
Electrode is seen in Super Smash Bros, were it will appear in the doorway on top of the Silph Co. building in the Saffron City stage. When it appears, it will explode, damaging any players that are near the door. In the sequels, it is released from a Poké Ball, where it will also explode. It can be picked up, and thrown at others, but must be done quickly, before it explodes.