Arusha the cheetah had been hand raised, and when he came to the San Diego Zoo, the staff felt he needed a companion. Another cheetah wasn’t a possibility, though—so they got him a dog: Anna, a golden retriever. This was an unusual decision at the time, but they thought the pairing might work because cheetahs are actually more like dogs in their temperament than like other types of cats. But when the trainers first introduced them, Arusha hissed and swatted at the dog. Anna didn’t defend herself, though, which puzzled the trainers. Then they realized she was trying to please them by not reacting! After that, they watched out of sight from around the corner.

Without the people present, when Arusha swatted at her again, Anna barked and stood up for herself—and Arusha backed off. Within a week, Anna was the boss. But she was also like a big sister; the pair had bonded, and they became best friends. As San Diego Zoo animal ambassadors, Arusha and Anna met thousands of Zoo visitors over the years.