The Vodníci of Charles Bridge
In Czech legend the Vodníci is a water spirit resembling a old man with green skin and with a beard like water weed. They are fond of drowning humans and eating them.
A coachman named Vincenc Sahul, who did not belive in the water sprite, once shouted out "Vodníci give me your skin to make a drum".
The engraged creature shouted back: "You country yokel with straw on your boots, you won't get my skin but I will have yours! You are dead at this very moment."
Shocked, the coachman said he was only joking and begged the Vodníci to spare him as he was about to be married. "You beg in vain; he who offends me receives a terrible punishment. If you have no headstone get one now." Then the water monster hauled the coachman, his coach and horses into the River Vltava where the coachman was drowned and eaten.