monkey wrench

brass monkey

Very cold.

cheeky monkey

An impudent person, usually a child.

get one's monkey up

To make someone angry, annoyed or irritated.

grease monkey

A mechanic, often with the specific connotation of an automobile mechanic.

like butter on a bald monkey

Very smooth.

make a monkey out of

To cause a person, group, or action to appear foolish or inferior; to subject someone or something to ridicule.

monkey around

To act foolishly.

monkey business

Activity that is mischievous, stupid, or time-wasting.