2 years old.
Cow: "Mooooove over"
Sheep: "Naaaaaaa."
or
Because the chicken was on vacation.
or
A snail because it carries it's home.
or
Because he want to wake up some day as America's First Dictator.
or
Bike helmets don't fit hippos
or
Clerk: "Yes, sir. What size does your alligator wear?"
or
A Dogwood
or
You can tuna piano, but you can't piano a tuna
or
Because they don't know the words.
or