Deer in the Headlights
If a person or animal is too frightened to move or think, then one can refer to him/her or it as being like a "deer in the headlights".

The origin of this phrase is literal and refers to deer's reaction of freezing when confronted with bright lights such as a car's headlights. At night the deer's eyes are fully dilated and when blinded by bright lights they cannot see and freeze until their eyes adjust; unfortunately this often leads to deer/vehicle collisions.

Use Example - Billy had such stage fright that when it was time for his presentation he was like a deer in the headlights.

Source Tags : Animal     Concept Tags : Fear