The Egg Cap

Once upon a time, a man was washing vegetables in a river when it washed an egg downriver and deposited it on the bank next to him. "What a strange egg," the man said. "It's big and has spots like nothing I've ever seen, and I've seen a few things, but not more than a few. Some neighbor upstream must have dropped it, some merchant or lord or wizard with all the best stuff. He must be missing this egg, so I'd better return it."
He didn't know a single person up the river who it could be, but he figured that had nothing with doing the right thing and placed the egg in his cap. The thing rolled around in there, as eggs often do, so he took off his socks and stuffed them in there. Satisfied with the arrangement's stability, he set off up the river.
The man stopped at every house along the way and asked if the egg belonged there, but the families there were honest and said they had never seen or owned anything like it. The houses gave way to farms, the farms to sparse woods, and the woods to areas where men never trod. He felt eyes on him, the eyes of unknown watchers, so every now and then he paused and raised his voice to ask him if anyone owned that egg. The eyes scattered each and every time.
The land climbed and he climbed with it, up slopes and over rocks green with moss. Higher and higher he climbed, till he found a lake high up, the river's source.
He approached the lake and looked for any house, tent, yurt, anything at all, but found nothing. Dismayed, he lifted his hat up and shouted, "Whose egg is this I have here? Don't let it get away because you're shy! You won't find another like it any time soon!" A beast roared in response. The man waited, and the beast appeared, a huge thing bigger than any of the houses where he asked, or maybe bigger than all of them. It was four-legged, a common way of getting around, and had three horns growing from its huge head. Is there any need to say he had never seen anything like it?
"You must be a lord or something, just like I figured," the man said. "Is this your egg? You want it back, of course."
The beast came right up to him, nodded, and pawed the ground. "Here?" the man asked, and set down the egg again. "There you go, and be sure to enjoy that egg. I'll be going now." He put his cap on and saluted the way he once saw a soldier do it.
The beast roared again and lifted its paw, which it waved and shook around in patterns the man had no chance of understanding. "Was I right about that too? Are you a lord and a wizard?" The beast nodded. "Wow! So what's that magic do?"
The beast slammed its paw down on his head with all its might. So sudden was the attack that he had no chance to move, and he was sure as anything that he was dead, but nobody came to greet him like the stories said they would. He opened his eyes. The beast and egg had both vanished. He made the long journey back, headbutting rocks along the way to confirm his cap was magically invincible. Word got around about it, and he sold the cap to a lord for so much money he never had to wash his own vegetables again. The lord did pretty well for himself too, as you would know if you ever met our king and saw him wearing that same shabby cap all these years later.
Finis