Imagine an African Lion, pump it up with steroids, put it in North America, and you have Panthera leo atrox, a.k.a: the American Lion. The American Lion is the largest cat ever. American Lions could grow 5 feet tall, 7.5 feet long, and weigh 700 or 800 pounds. Even this cat's bite was big. It had a bite force of 1,800 pounds. Although the American Lion had the same number of teeth as an African Lion, they were 25% larger. This made the American Lion even bigger than a Siberian Tiger.