Jaguars are the largest of the big cats in the Western Hemisphere. The spotted cats, which roam up from Argentina to the U.S. southwest, play a key role in the mythology of several ancient American cultures including the Aztecs and the Maya, who believed the powerful cats as their companions in the spiritual world. Jaguars are the largest of the big cats in the Western Hemisphere. The spotted cats, which roam up from Argentina to the U.S. southwest, play a key role in the mythology of several ancient American cultures including the Aztecs and the Maya, who believed the powerful cats as their companions in the spiritual world.