The animal, which was caught on camera in Aquetong Spring Park in Solebury Township, is about 20 inches tall with black hair, police said.
Police said they are now looking to see if anyone in the area is missing a large black domesticated cat.
Anyone who sees the animal is asked to stay far away and contact police at 215-328-8511.
Police said they briefly closed the park on Wednesday after a concerned citizen spotted the animal roaming the trails.
The park reopened a short time later.