Zorpians

Zorpians are a subspecies of humans that have 4 arms and 2 heads. They live a much shorter life than humans because they cannot produce enough blood to work 2 brains and 4 arms, but while they are living they are very smart and most zorpians grow up to be scientists. They also grow 2x as fast as normal humans. They live on the planet hippo-jobbly. As a whole throughout the classic verse their species population is only around 9 billion.