Twenty. One to hold the bulb, two to turn the ladder, and 17 to be on the guest list.
or
In their Sleevies!
or
Two. One to hold the bulb and the other to rotate the planet.
or
Take away his credit card
or
Three skunks fighting over a pickle
First dog: My master calls me Furball. How about you?
Second Dog: My master calls me Sitboy
or