VOLTORB was first sighted at a company that manufactures POKé BALLS. The link between that sighting and the fact that this POKéMON looks very similar to a POKé BALL remains a mystery.
Sapphire:
VOLTORB is extremely sensitive - it explodes at the slightest of shocks. It is rumored that it was first created when a POKé BALL was exposed to a powerful pulse of energy.
Fire Red:
A life-form whose identity is unknown. It is said to SCREECH or suddenly SELFDESTRUCT.
Leaf Green:
Usually found in power plants. Easily mistaken for a POKé BALL, it has zapped many people.