It was a bitter cold rainy day, a very long time ago when knighthood was in flower, as the saying goes. Sir Galahad, the pride of King Arthur's round table, set forth on a mission of derring-do.
The weather turned worse and soon the rainy day grew into a raging storm. Galahad's horse, stumbling and exhausted, might have collapsed in another minute, but fortunately toward nightfall they came across a tavern. Grateful for this unexpected sanctuary, Sir Galahad rushed inside and warmed himself by the fire. His horse, poor creature, was bedded in the stable, safe at last from the howling elements.
"Innkeeper" said the knight, "if you will provide me with another horse I will be on my way."
"What's the big rush in such rotten weather?" The innkeeper wanted to know. "I'm thinking of slaying a dragon," answered Sir Galahad. "I'll save you some of the meat."
"Feh! Dragon flesh my people don't eat! But no matter, a horse I haven't got for you anyway."
"But I'm a bold knight," protested Sir Galahad. "If you haven't a horse for me, how about that big mastiff lying there by the fire?" pointing to the sleeping hound that was almost the size of a small horse wearing a large studded collar that was chained to the wall of the inn.
"Sir Galahad," thundered the innkeeper indignantly, "I wouldn't even consider sending a knight out on a dog like this!"