Originally an "inscription" and then simply a short poem, now either a short poem with a brief, pointedly humorous, quotable ending or simply a terse, witty statement in and of itself.
Inscribed on a collar given for a dog belonging to Frederick, Prince of Wales, at his estate in Kew: "I am His Highness' dog at Kew -
Pray tell me, sir, whose dog are you?" — A. Pope
Here lies my wife: here let her lie! Now she's at rest - and so am I. — John Dryden
Some cause happiness wherever they go, others whenever they go. — Oscar Wilde
I can resist everything except temptation. — Oscar Wilde