Tell us about Sleipnir (is that how it's spelled?) the eight legged horse.
OH MAN THIS ONE
One of the most (in)famous of Loki’s shenanigans.
So. Shortly after the construction of Asgard, the gods were going about their business when a stranger arrived at their gates. He offered his services to construct a wall for them around Asgard, one that would never fall. He swore that he would do this in a mere three seasons, which seemed impossible, and as payment for his services he wanted the hand of Freyja, the beautiful, in marriage, as well as the sun and the moon.
The gods went into a huddle at this to discuss things.
“Fuck this guy.” Announced Freyja. “In the metaphorical sense, not the literal. I’m not marrying him.”
“Anyway, yeah, this is a scam.” Odin said. “I know a scam when I see a scam, and this is definitely a scam, and you know what we do to people who try to scam us.”
“What the fuck you two, Loki, shut the hell up, that isn’t what he…”
“Exactly, thank you Loki. We counter scam them. Here’s the plan.”
*Some time later*
“Fine. Fine. I’m in. But know that if he pulls it off, I will kill both of you. Slowly. And use your skulls as food dishes for my cats. And also kill him on the wedding night.”
So the gods returned to the craftsman and agreed, with a condition; he would only have one season to complete the work, and it must be done without any aid save that of his horse.
“Deal.” He agreed immediately. “But you’ve all gotta swear a binding oath that you will keep your word.”
The myth does not specify that he was, specifically, eyeballing Loki and Odin at that part, so I am forced to assume that he was.
The gods all do. The craftsman gets straight to work, and the wall begins going up at an impressive pace. As Freyja’s scowl deepened, it was noticed that the man’s mighty stallion, Svadilfari, was doing most of the work, hauling stones larger than any normal horse could shift and never seeming to tire.
“It’s fine!!!” A sweating Loki assures a glowering Freyja. “Just fine! The horse will tire, he won’t finish it!”
But winter wears on, the wall grows, and it’s soon clear that the horse will not tire, and the man will indeed complete his work. Freyja has taken to making throat-cutting gestures at both Odin and Loki whenever she sees them.
Three days from the end of winter, and only the final layer of stones for the gates need to be laid. I picture here Odin and Loki watching the mason pack up his tools and horse for the evening and ride off, secure in the knowledge that he will soon wed Freyja and take the sun and moon.
“He could do it.” Loki squints up at the wall.
“Yep.” Says Odin, sipping mead.
“He’s a frost giant, isn’t he?”
“Got this won, he has.” Loki nods, sipping his own mead.
“Freyja cornered me today and threatened to feed my balls to her cats.”
“She’s going to use my remaining eye as a necklace too, apparently.”
“She’d make it painful, too.”
“Yep.” Odin refills both their ale horns with mead. “Because, of course, there is no one in Asgard who would, in this situation…how did you put it the other day?”
“Cheat like a motherfucker.”
“Yes, that’s it. No one at all.”
“I’ve got a plan.”
A grin from the Old Bastard, a sort of half smirking wolfish grin. “I knew you would.”
They then clink mean horns and cackle like hyenas for a full minute and a half.
The next day, the mason arrives for his work and begins cutting more stones as his stallion grazes. As he works, a pretty young mare prances out of the woods, tossing her mane and tail and giving Svadilfari come-hither glances.
Svadilfari sniffs, decides in .000000003 seconds that a young mare in season is infinitely more interesting than hauling rocks, and takes off after her. The mare dashes ahead of him, staying juuuuuuust out of reach as the giant swore and cursed back by the sledge.
The mare, of course, is Loki. He leads Svadilfari a merry chase, but is still Loki, and allows herself to be caught eventually. Loki and Svadilfari proceed to have a grand few days in a nice clearing in the woods, far from Asgard and Svadilfari’s master.
Meanwhile, the three days come and go. The giant tries his hardest, but cannot finish the wall without Svadilfari. At last the sun sets on the end of the season, and the wall remains unfinished. He has not completed his task, and Freyja and the sun and moon are lost to him.
“YOU CHEATED!!!” He presumably yelled, swelling to giant size and revealing himself as a frost giant at last.
“I didn’t do a single thing,” Says the Allfather, which to be fair is technically true. "Go from this place. You have lost.“
The enraged giant did not. Therefore, he was paid, instead of his wages, a blow of Thor’s hammer to the head, which shattered his skull and killed him on the spot.
Loki did not return for many months, though there were sightings in the forest of a pretty mare with an eight legged foal on occasion. Finally, Loki reappeared at the gates of Asgard with a weanling foal in tow. The foal had eight legs, and followed Loki as a young horse will its mother. The gods all, presumably, gave each other Significant Looks at this.
Loki took the foal before Odin, who also presumably raised an eyebrow.
“You know, you didn’t have to do it that way, but good job.”
“Hey I didn’t question the whole tie yourself to a tree thing, you don’t question my methods. Also, this is Sleipnir. Sleipnir, this is Uncle Odin. You stick with him and be a good boy, okay? Remember, mommy loves you and will come to visit but you’re a big boy now and I need to get back to my other interests.”
And that is how Odin obtained Sleipnir, the eight legged steed that carries him through the realms.