Savannah cats are actually a domestic breed. Licensed breeders breed certain types of housecats with wild Servals to create the F1 savannahs, while F2-5 are bred Savannah-to-housecat. While not as common as havannah browns, persians and other expensive breeds, the are actually just as much housepets as the others. They're high energy and (funfact!) they can even be trained to walk on a leash and play fetch. He's an escapee from a pet-owner or a licensed breeder.

--- Just realized what I jotted down in other. He's not actually a wild leopard cat. Because of their size and relative rarity, Savannahs can be accidentally mistaken for zoo escapees among other things. That was more of a news-title handed out for attention.