Jake Gardiner was walking in the woods in the foothills of La Crescenta, a suburb of Los Angeles, when he heard rustling in the trees. He recorded video on his mobile phone and later noticed what many are saying looks like an ape-like creature swinging around the branches.
"It could be some kind of ape, it also could be a bear, it could be a large bird," says Andrew Hughan, a spokesman with the California Department of Fish and Wildlife.
He added that it could be someone's pet but it's difficult to say based on the blurry video and lack of physical evidence.
"It's an interesting mystery right at the moment, and we'll see what happens," he says.