Don't be such a scaredy cat, it's just a little spider.
scaredy mouse
Frequency:
40
%
She's always been a scaredy mouse when it comes to horror movies.
scaredy rabbit
Frequency:
25
%
He's a scaredy rabbit when it comes to roller coasters.
Idiomatic Expressions for scaredy pants
Phrase: don't be a scaredy pants
Meaning: encouragement to not be afraid or timid
Usage: Come on, don't be a scaredy pants, just jump off the diving board!