From the back seat of the car, crocoKid sings:

"This old man, he plays two
he plays knick-knack on your poo!

"HA AHH HAHAH HA!

"This old man, he plays three
he plays knick-knack on your pee!

"HEE EEH HEHEE HEE!"

With a knick-knack paddywhack,
give a dog a phone.
This old man went rolling home!