*funny as a barrel of monkeys
 Cliché very funny. (*Also: as ~.) Ron was as funny as a barrel of monkeys. The entire evening was funny as a barrel of monkeys.

I'll be a monkey's uncle!
 Fig. I am amazed! A: I just won $500,000 in the lottery! B: Well, I'll be a monkey's uncle!

make a fool (out) of someone and make a monkey (out) of someone
 to make someone look foolish. John made a monkey out of himself while trying to make  a fool out of Jim. John made a fool out of himself at the party. Are you trying to  make a monkey out of me?
 
mess with someone or something and monkey with someone or something
 to bother or interfere with someone or something. Come on, don't monkey with my new   camera. Don't mess with me unless you want trouble.

monkey business and funny business
 silliness; dishonest tricks. That's enough monkey business. Now, settle down. Stop  the funny business. This is serious!

Monkey see, monkey do.
 Prov. Children imitate what they see other people doing. I don't let my children  watch TV programs that show kids being disrespectful to their elders. I know what  would happen if I did: monkey see, monkey do.
 
monkey suit
 a tuxedo. (Jocular. Possibly in reference to the fancy suit worn by an organ- grinder's monkey.) Do I have to wear a monkey suit to dinner? All the men except me  wore monkey suits at dinner on the cruise.

more fun than a barrel of monkeys and as much fun as a barrel of monkeys
 Cliché a great deal of fun. (Compare this with as funny as a barrel of monkeys.)  Roger always makes me laugh! He is as much fun as a barrel of monkeys. The circus  was more fun than a barrel of monkeys.

throw a monkey wrench in the works
 Fig. to cause problems for someone's plans. I don't want to throw a monkey wrench in  the works, but have you checked your plans with a lawyer? When John suddenly refused  to help us, he really threw a monkey wrench in the works.
 
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.