The Devil's Dictionary

CERBERUS, n. The watch-dog of Hades, whose duty it was to guard the entrance-against whom or what does not clearly appear; everybody, sooner or later, had to go there, and nobody wanted to carry off the entrance. Cerberus is known to have had three heads, and some of the poets have credited him with as many as a hundred. Professor Graybill, whose clerky erudition and profound knowledge of Greek give his opinion great weight, has averaged all the estimates, and makes the number twenty-seven--a judgment that would be entirely conclusive if Professor Graybill had known (a) something about dogs, and (b) something about arithmetic.

AMBROSE BEIRCE, page 14.
:-)