Here's a bit of preamble that might be useful, too - some epithets and associations:
He is spoken of variously as the Old King, Mananan of the Flames [the least common name], the King of the Wanderers, the Sailor's Friend, and--most intimate and frequent of all the names-Himself. There are stories of his calling people away to his secret Island of Immortality beyond the western sea, or appearing to sailors or fishermen in danger and helping them-sometimes in distant parts of the world. He is the patron (sometimes openly acknowledged but oftener not) of sailors and beggars and poets and all careless wandering people; he has been seen rolling and leaping along the summits of the middle mountains in the form of a wheel of fire; and he is never very far away from the hills of his Island, or from the imaginations of his people when they speak or think of the unseen world.The following story is called simply "Manannán and the Shepherd", recorded "from the top of Laxey glen, and relates to the same district" on the Isle of Man:
There was a man living up at the Griananes one time, and he had sheep on the Big Mountain [Snaefell]; and one day he was up after them alone on a middling thick evening in the winter. He had them all nearly gathered in a quiet corner ready for counting, and was thinking of making tracks before the dark would come on him, when he seen a big coarse-looking man and him all like in ragged clothing, coming straight for him through the mist.
"Good evening to thee, master," he says; and "Good evening to theeself," says my bold boy.
"It's a fine lot of sheep thou have there."
"Aw, middlin', middlin'. I'm just for counting them before I'll make tracks for home."
"A hard task, that," says the stranger.
"No, not hard at all when ye know the way," says the farmer - but the words weren't hardly out of his mouth till he heard a mighty big laugh and a sound like a little mocking tune. And behold ye, when he looked around him there wasn't a sign of a sheep nor man nor anything at all, only thick, thick mist going swirling around him, and a high wind blowing. And he heard a big voice shouting out in the wind:
"Count thy sheep now, master! Count thy sheep now! Do thou know the way, master?"
Well, he knew then that it was some fairy making gammon of him, but he was wild atchim [Manx: 'terror'] and started trying to find his way out of the mist. But no use at all, for it wasn't minutes till he was in a strange country altogether, and big, high rocks all standing round in the mist fit to frighten you, and all like the noise of water falling down in deep gullies and places, till he didn't know where he was at all. And the dark begun to come on, and then he knew he was fairly took, so he sat down and waited till the thing would lift off him.
But no sooner did he sit down and give in than he found the Big Ragged Fellow standing in front of him and saying:
"Didn't I give thee a fine race now, and wasn't it a hard task to count thy sheep for all? But sit you there now, and I'll make the hard task easy." And then the Big Fellow drove the sheep right past, slow and plain that he could see the mark on every one, and right into the same corner where they were before; and then the man found he was close on the track going down the glen for home.
"What sort of a wandering fairy-man art thou, playing tricks on a poor fellow that never did thee no hurt?" he said. But behold ye, when he looked at the Big Fellow again he was taller than ever, and a sort of shine around him, and like going away up the Big Mountain in the mist. And a soft, easy voice come slipping down the hill - not the same voice at all that was shouting and mocking at him before, only he knew it was coming from the Big Fellow - and it said:
"Who would I be, only the King of the Wanderers, travelling the land and playing pleasant tricks on the like of yourself for my own diversion? But thou'll be none the worse for thy race arounnd the mountain!"
And he wasn't neither, for he had great luck with all his stock from that on, and came to be the richest man in the parish.
'Mananan -The Sea God of Mann' From A Correspondent in the Isle of Man.
Journal of the Folk-Song Society, Vol. 7, No. 28, Manx Collection Part I (1924).