Knock me down and call me shorty!

Meaning

An expression of extreme surprise or disbelief. It is the verbal equivalent of a jaw dropping to the floor.

Exclamatory, humorous

Used in a sentence

• Well, knock me down and call me shorty, I never thought he would win the lottery!
• Knock me down and call me shorty, I cannot believe you finally finished that project.
• If they actually show up on time, well, knock me down and call me shorty.