Because he was under cover.
or
When it came time to pay, the skunk didn't have a scent, the deer didn't have a buck so they put the meal on the duck's bill.
or
Fifty — one to screw in the bulb and 49 to guard him/her.
or
A New Jersey.
or
He was tired of working for peanuts.
or
She was the fairest in the land.
or