When Argentinian woman Florencia Lobo and her brother found two kittens next to a dead adult cat near the Santa Rosa de Leales settlement in Tucuman province, they decided to take them home.
"We thought that it was an abandoned cat who had given birth," Ms Lobo told Reuters.
She said they took both kittens home, but one, a female, was too weak and didn't survive.
The other kitten was a male, and she named him Tito. He seemed to be healthy, but she took him for a check-up after two months – only to learn he wasn't a regular cat!
"The vet didn't know what it was but said it was not a normal cat and gave me the number of the reserve," Ms Lobo said.
She contacted the Horco Molle nature reserve, who confirmed it was a puma jaguarundi, a small wild cat native to American territories from Arizona to Argentina.
Tito is now being cared for at the reserve, in preparation for a return to his habitat.