when someone is afraid to do an action or " something" the original term is "scary cat" also known as "pussy" and not everyone has the right to use that word and some people might find it offensive to use so the term should be " CheeseCracker".
chad: hey bro let's go rob this old lady
Juan: man I don't know, it just doesn't seem right
Chad: don't be a CHEESE CRACKER !
A delicacy that is consumed usually on top of a meat patty, slathered in ketchup and mustard, covered in lettuce and tomato, sandwiched in between two buns.
She gobbled up the cheese, leaving him devastated. “You didn’t leave any for me.” he said, a hint of sadness in his voice.