A Good Samaritan found the severely injured animal Thursday afternoon in Philadelphia's Kensington section on F Street near McPherson Square Park.
"It was crying when I was picking him up, but when I moved him in the back, he was screaming," Damaris Alcala said.
It's now in the care of veterinarians.
The SPCA says the baby cat has burns over a third of its body.
"It is unusual, whether it's just young kids doing as a prank - what the reason is, I have no idea, but it's pretty horrendous," SPCA spokesman George Bengal said.
Police seized surveillance from a nearby store hoping it can provide clues as to who did this.