This is the shocking moment a deer suddenly became aggressive and attacked a scooter rider in a park in China.

Footage shows the helmeted motorist petting the sika deer by the roadside in Shanghai on July 23.

Moments after he withdrew his hand, the clingy hoofed creature butted his arm with its head.

The startled man pushed the animal away, triggering it to lash out, repeatedly kicking him in the face until he lost balance on his motorcycle.

The deer continued its assault, standing on its hind legs and striking with its front limbs, even biting the man's back as he screamed in pain.

Fortunately, another motorist stepped in to scare the deer off.

Both men later burst into laughter while the confused animal stood motionless in front of them.

The rider reportedly did not sustain any injuries from the attack.

Deer may behave aggressively when they feel threatened, are provoked, or seek attention, especially in areas where humans frequently feed them. While their bites are rarely harmful, their hooves can inflict serious injuries.