One of those ice-breaker activities you probably did in Boy Scouts or at a retreat when you were in high school. The leader stands up in front of the group (who have mostly never heard this before), and recites the following from memory, pausing between each "stanza" so that the group can repeat everything they say. Starts out easy, then gets progressively more ridiculous. And it goes a little something like this:

Allright, we're going to play a memory game. What I want you to do, is repeat back to me what I say to you. Are you ready?

One hen

One hen
Two ducks

One hen
Two ducks
Three squawking geese

One hen
Two ducks
Three squawking geese
Four limerick oysters

One hen
Two ducks
Three squawking geese
Four limerick oysters
Five corpulent porpoises

One hen
Two ducks
Three squawking geese
Four limerick oysters
Five corpulent porpoises
Six pair of Don Alvarso's tweezers

One hen
Two ducks
Three squawking geese
Four limerick oysters
Five corpulent porpoises
Six pair of Don Alvarso's tweezers
Seven thousand Macedonians dressed in full battle array, hey!

One hen
Two ducks
Three squawking geese
Four limerick oysters
Five corpulent porpoises
Six pair of Don Alvarso's tweezers
Seven thousand Macedonians dressed in full battle array, hey!
Eight brass monkeys from the ancient sacred crypts of Egypt

One hen
Two ducks
Three squawking geese
Four limerick oysters
Five corpulent porpoises
Six pair of Don Alvarso's tweezers
Seven thousand Macedonians dressed in full battle array, hey!
Eight brass monkeys from the ancient sacred crypts of Egypt
Nine apathetic, sympathetic, diabetic old men on roller skates, with a marked propensity towards sloth and procrastination

One hen
Two ducks
Three squawking geese
Four limerick oysters
Five corpulent porpoises
Six pair of Don Alvarso's tweezers
Seven thousand Macedonians dressed in full battle array, hey!
Eight brass monkeys from the ancient sacred crypts of Egypt
Nine apathetic, sympathetic, diabetic old men on roller skates, with a marked propensity towards sloth and procrastination
Ten lyrical, spherical, diabolical denizens of the deep who haul quay around the quo of the quivvy of the quarry, ALL AT THE SAME TIME!

Usually, by this time the group has dissolved into giggles or wants to kill you. Apparently there are ten more verses to this somewhere, eleven through twenty, but I don't know nine of them, and I've never been brave enough to continue to:

Eleven neutramatic synthesizing systems owned by the seriously cybernetic marketing department, shipped via relativistic space flight through the draconian sector seven