"Y"?

A Yahoo Yelled at his Yak to stop Yapping Yarns about Yuppies.
Ying and Yang Yelped
"Yoiks!"
when they got the Yen.
The Yankee Yawned when he smelled the Ylang-Ylang.
A Yogi Yodeled when he had Yellow fever.
Yahweh played with a
Yellow Yo-Yo
In his Youth.