The complete Pokemon RBY pokedex, part 10

Pokémon Name: Voltorb
Type: Electric
Classification: Ball Pokemon
Pokédex Number: 100
Ability: Soundproof and Static
Dream World ability: Aftermath
Useful Attacks: Selfdestruct
Location Found:
D/P/P: Swarm in Route 218
HG/SS: Route 10
B/W: Poke Transfer

Pokemon number 100 is none other than Pokeball look-alike Voltorb. Consider scooting it along to its evolved form, Electrode.

Evolution: Electrode at 30