Simple and Direct:
* Jumpy: This emphasizes the suddenness and exaggerated response to fear.
* Frightened easily: This is straightforward and accurate.
More Vivid and Figurative:
* A startled deer in headlights: This image conveys helplessness and panic.
* A house of cards: Suggests that their composure is fragile and easily toppled.
* A porcelain doll: This implies fragility and delicate emotions.
* A skittish cat: Highlights nervousness and quick responses to perceived threats.
* A moth drawn to a flame: Represents being drawn to danger or risky situations despite fear.
More Abstract and Powerful:
* Haunted by shadows: Indicates fear and anxiety that lingers even in safe situations.
* A prisoner of their own fears: Emphasizes the debilitating effects of fear.
The best metaphor for "scared easily" will depend on the specific context and the overall tone you want to convey. Consider what you want to highlight (e.g., fragility, helplessness, quick responses) and choose a metaphor that best captures that aspect.