1889 (pub): M'Hardy's Luck
Back in the time before carts were much in use, and everything had to be carried on the backs of horses, a Scottish farmer named M'Hardy set out one dark night from Brochroy to go to the Garchory mill to fetch home some meal for his wife and children. Upon arriving at the mill, M'Hardy left his horse at the door as he went in to get the bags of meal... and the lazy animal turned around and started walking home the minute it wasn't supervised, leaving M'Hardy no good way to transport the load of meal home. Upset, the Scotsman bemoaned aloud "Ma wife an bairns 'ill be a' stervt for wint o' mehl afore I win hame. I wis I hed ony kyne o' a behst, although it war a water kelpie" ("My wife and children will be starved for want of meal before I get home. I wish I had any kind of beast, although it were a water-kelpie").
Hardly were the words spoken when a horse with a halter over its head appeared. M'Hardy approached the new found horse, which proved to be very gentle... it put its head right on the man's breast. The farmer was overjoyed with his luck, and he loaded the horse and led it home to his farm-house. On arrival, the new horse was tied off on an old harrow so it wouldn't wander until M'Hardy was able to unload the meal and take it all into the house. When M'Hardy came back out with the intent of taking the gentle horse to the stable, he discovered that not only was the new horse gone, but the old harrow it had been tied to was also missing. Off in the distance, he heard the sound of a beast plunging into a big pool of the Don (presumably a lake or river) that was near the house. Looking in the stables, M'Hardy found his own horse standing quietly in it.
My Source's Source
The above tale was published in 1889 by the Reverend W. Gregor, who heard the tale from Mr. J. Farquharson, a mason in Corgarff, Scotland, described as "a man of great intelligence, and a mine of folklore"... which, frankly, is not a bad way to be remembered!
This is one of the few tales where, for unknown reasons, a water-horse -- a well-known Scottish lake monster also sometimes called a 'kelpie' -- has elected to help a human, instead of eating them. Only the water-horse could explain why, I fear.