Hobbes will not allow Calvin to enter the clubhouse until he finishes extolling the virtues of tigers:

Verse Six:
Tigers are nimble
And light on their toes
My respect for tigers
Continually grows.

It should be noted that after five versus, Calvin will nolonger do the dance that usually accompanies this recital.

This just in: The Seventh Verse Extolling Tigers has just been found!

Verse Seven:
Tigers are perfect,
The e-pit-o-me
Of good looks and grace
And quiet dignity.