The Colorado runner who killed a mountain lion with his bare hands was actually wrestling with a kitten, officials said Thursday.

Travis Kauffman was attacked earlier this month while jogging at the Horsetooth Mountain Open Space — by a big cat that was about 3 or 4 months old, according to the Coloradoan.

The kitten weighed about 34 to 40 pounds when alive, according to the final necropsy report conducted by a Colorado Parks and Wildlife veterinarian.

Other animals, including the dead lion’s siblings, had started to chow down on his remains, so he weighed about 24 pounds when officials found him.

Officials believe the animal was male, though it was hard to tell, since its sex organs seemed to have been scavenged.

The 31-year-old Kauffman, who stands 5 feet 10 and weighs 150 pounds, said that during his 10-minute struggle with the lion, he hit the animal on the head with a rock and then stepped on its throat, ultimately suffocating it.

Kauffman suffered minor injuries to his face and neck, hand, back and thigh.

Wildlife officials said even though the lion was young, Kauffman did everything right in defending himself.