Loki

He put on his shoes that let him travel through the sky, and he went to Svartalfheim, where the dwarfs have their workships. The most ingenious craftsmen of all, he decided, were the three dwarfs known as the sons of Ivaldi.
Loki went to their underground forge/ Hello, sons of Ivaldi. I have asked around, and people here tell me that Brokk and Eitri, his brother, are the greatest dwarf craftsmen there are or have ever been," said Loki.
"No," said one of the sons of Ivaldi. "It's us. We are the greatest craftsmen there are."
"I am assured that Brokk and Eitri can make treaures as good as you can."
"Lies!" said the tallest of the sons of Ivaldi. "I wouldn't trust those fumble-fingered incompetents to shoe a horse."
The smallest and wisest of the sons of Ivaldi simply shrugged. "Whatever they make, we could do better."
"I hear they've challneged you," said Loki. "Three treatures. The gods of the Aesir will judge who made the best treaure. Oh, and by, the way, one of the treatures you make needs to be hair. Ever-growing perfect golden hair."
"We can do that," said one of the sons of IValdi. Even Loki could barely tell them apart.
Loki went across the mountain to see the dwarf called Brokk, at the workshop he shared with his brother, Eitri.
"Ivaldi's sons are making three treatures as gifts for the gods of Asgard," said Loki. "The gods are going to judge
the treasures. Ivaldi's sons want me to tell you that they are certain you and your brother Eitri can't make anything as good as they can. They called you 'fumble-ginered incompetents'."
Brokk was no fool. "This smells extremely fishy to me, Loki," he said. "Are you sure this isn't your doing? Stirring up trouble between Eitri and me and IValdi's boys seems like the sort of thing you'd do."
Loki looked as guileless as he could, which was amazingly guieless. "nothing to do with me," he said innocently. "I just thought you ought to know."
"And you have no personal stake in this?" asked Brokk.
"None whatsoever."
Brokk nodded and looked up at Loki. Brokk's brother, Eitri, was the great craftsman, but Brokk was the smarter of the two, and the more determined. "Well, then we'll be happy to take on the sons of Ivaldi in a test of skill, to be judged by the gods. Because I have no doubt that Eitri can forge better and craftier things than Ivaldi's lot. But let's ake this personal, Loki. Eh?"
"What do you have in mind?" asked Loki.
"Your head," said Brokk. "If we win this contest we get your head, Loki. There's lots of things going on in that head of yours, and I ahve no doubt Eitri could make a wonderful device out of it. A thinking machine, perhaps. Or an inkwell."
Loki kept smiling,b ut he scowled on the inside. The day had started out so well. Still, he simply ahd to ensure that Eitri and Brokk lost the contest; the gods would get six wonderful things from the dwarfs, and Sif would get her golden hair. He could do that. He was Loki.
"Of course," he said. "My head. No problem."