A word for someone who gets scared easily

I have looked online and most websites reference words such as cowardly and spooked. Those however don't seem to reflect what I am looking for.

I am looking for a simple word to call someone who gets scared easily.

Sample sentence:

Bob is so _______. He gets scared so easily!

Solution 1:

skittish (Webster)

adjective 1. apt to start or shy: a skittish horse. 2. restlessly or excessively lively: a skittish mood. 3. fickle; uncertain. 4. shy; coy.

Solution 2:

Bob is a scaredy–cat. He gets scared so easily.

scaredy–cat: an unduly fearful person.

Credits: @bill

Solution 3:

Bob is so jumpy. He gets scared so easily.

jumpy: subject to sudden, involuntary starts, especially from nervousness, fear, excitement, etc.

Solution 4:

Bob is timid.

Timid

Pronunciation: /ˈtimid/

ADJECTIVE (timider, timidest)

Showing a lack of courage or confidence; easily frightened:

I was too timid to ask for what I wanted.

(Source: Oxford Dictionaries)