According to experts the best captions in descending order are observational, anecdotal, satirical, farcical, ironic, parodic, hyperbolic, epigrammatic, sarcastic, and finally, puns. If you are unable to come up with any of the above try quoting from the dictionary: Hedgehog - a small nocturnal mammal with a spiny coat and short legs, able to roll itself into a ball for defence.