“Never look a gift lion in the mouth.”
“Never look a gift horse in the mouth.”
“Neither look the gift-horse in the mouth or stand too close behind.”
“A lady lion-tamer put her head in a lion's mouth last week, and he bit it off. If a lion attempted to put his head in my mouth I expect I would do the same.”
“Never look a gift horse in the magazine well.”
“On the other hand it was bad manners to look a gift horse in the mouth. Even if you're getting it from an overweight cracker in a fringe shirt.”