The blanket octopus is rarely seen, especially the tiny males. Measuring barely an inch long, the males are dramatically smaller than females. Female blanket octopuses grow more than six feet long, and are up to 40,000 times heavier than males and about 100,000 bigger. To put this in perspective, imagine a full-sized human female next to a walnut-sized male. The blanket octopuses exhibit the largest sex size discrepancy in the animal kingdom.