rock bird
You're so hungover that when a bird is flying towards you, you see its shadow on the ground and think it's actually a rock being thrown at you. Also applies to other flying species like butterflies.
Hungover dude: "OMG did you see who threw that rock at me?"
Hungover friend: "Don't worry man I felt it too, it was just a rock bird."
Hungover friend: "Don't worry man I felt it too, it was just a rock bird."