Loki, to stop a Jotun from completing the great wall he was building around Asgard with the help of a very strong horse called Svadilfari, turned himself into a beautiful mare to distract the stallion. Loki so excited Svadilfari that he ran away from the Jotun and followed the mare into the forest. Loki went out of his way to keep the great stallion with him in the forest, ( The Gods had threatened Loki for allowing the Jotun to use the horse in the first place ), and as a consequence of his disguise he sometime later bore the eight - legged foal named Sleipnir, which became the best of all horses, and was used by Odin himself, and borrowed by Hermod to visit Balder in Niflheim.
Thor, when he went fishing for the Midgard Serpent, disguised himself as a young boy to fool Hymir into letting him go fishing with him. This deception worked so well because Hymir at first did not even want the young boy to go with him saying that he was only a scrap of a fellow, and would catch cold that far out at sea. Thor assured Hymir that he could row far out to sea, and in the end Hymir decided to let the boy join him. Thor of course catches the Midgard Serpent, but just as he raises his mighty hammer to strike the death blow, Hymir, who by now is terrified, cuts the line with his knife and the Midgard Serpent sinks back down into the abyss.
In the story of the death of Balder it is said that to allow him to leave Niflheim, and return to the land of the living, everything in the worlds must weep for him. Messengers were sent out to the corners of the worlds, and everyone, and everything, agreed to weep for Balder except a Giantess who was sitting in a cave. She refused to weep for the son of Odin, and therefore Balder was held firmly in the grip of Hel. It goes on to say that the " Giantess there was Loki, Laufey's son, who has done the most harm amongst the Aesir. Obviously he had shape changed to fool the messengers.
The murder of Balder angered the Gods so much that Loki fled for his life, and hid himself in the mountains. He was so scared that he built a house with four doors, each facing in a different direction. During the day he liked to change himself into the shape of a salmon, and hid in the waterfall. It was in this river that the Aesir caught Loki, after several tries, and brought him back to Asgard to face trial for his wicked deeds, and be punished.
Loki also seems to have the ability to change others into another form as well, as we see in the story of the kidnapping of Idunn, for which he was both the rescuer and the accomplice. He is forced to agree to a Jotuns demands for Idunn, and lures her with her apples outside the gates of Asgard. When the Aesir begin to grow old and gray without the youth sustaining apples that Idunn takes care of for the Aesir, they threaten Loki and force him to act on their behalf. Loki then borrows Freyja's falcon coat, and flies to Giantland to get her back from the Jotun Thjazi. Loki was lucky because when he arrived Thjazi was out rowing, and had left Idunn at home alone, and unprotected. Loki then turns Idunn into the form of a nut, takes her in his claws, and then flies back to Asgard with her. Now that is not the end of the shape changing in this story. Thjazi, when he comes home and finds Idunn missing, assumes the shape of an eagle and flies out after the falcon. Seeing this the Asgardians took plane shavings and lit them on fire. Loki was able to get past the blaze, but the larger eagle came too close and burned his wings and fell to the ground where the Gods killed him.
Odin gets into shape changing as well ! While traveling as Bolverk, Baugi makes a deal with him that if he does the work of his nine serfs, who were killed by Odin, he would try to get his brother Suttung to allow Bolverk one drink of the mead of poetry. Suttung upon hearing this promptly refuses of course. Bolverk ( Odin ) uses the auger called Rati to bore through the mountain where the poetic mead is kept. Bolverk then turns himself into a serpent, and slithers through the hole. Baugi tries to stab at him with the auger but misses him. Deep within the mountain Bolverk, returned to his manly form, sleeps with Gunnlod and drinks all of the mead of poetry. When he was finished he turned himself into an eagle and flew back towards Asgard. Seeing an eagle flying away from his fortress Suttung guesses what happened and turns himself into the shape of an eagle as well. Odin as he flew over Asgard spits out the precious mead into crocks that the Aesir had left out into the courtyard.
End Part 1.
Next : Part two of the Shape Changers.
Go with Odin's wisdom, Freyja's love, and Thor's protection !