Loki is the god of mischief in Norse mythology and is infamous for shape-shifting and changing his sex according to his preferences. In the legends, he was not the bother of Thor, nor was he the son of Odin. He was the son of a giant named Fárbauti. He was allowed to join the gods and was included in their tribes.

Legend has it that though he was the god of mischief, he did continuously help Thor and Odin in their lives and was very clever in coming up with new things to add to their plans. There were a few children who he fathered. It is known that he shape-shifted and reproduced according to his likings.

Hel

Hel is an offspring of Loki, who was born from the giantess Angrboda. Angrboda was known as the bringer of disaster, and the combination of both her and Loki produced one of the strongest goddesses in Norse mythology. Though there are bleak sources on this, it is said that Hel or Hela was more powerful than Odin when she was in her own realm. Her realm was the Niflheim where a portion of souls was sent. These souls were supposedly of those who had died of disease and old age.

She also denied Baldr being released from Niflheim when his brother came to take him along back to their realm.

Jörmungandr

This creature is the middle child of Loki and Angrboda. Jörmungandr was known to be thrown into the sea by Odin since he was told that these three children would bring about great destruction for the gods.

This child apparently grew so big that it was able to circle the earth and bite its own tail. When Jörmungandr will release his tail, it will start Ragnarok. This will be the doom of the earth. If you are interested in Norse mythology and fantasy, you should read books such as Minerva Pearlstar And The Weavers Of Fate. It is a mythological fantasy book which revolves around Loki and a child named Minerva. An interesting plot which is fun to unfold.

Fenrir

Fenrir is also the child of Angrboda and Loki. He is a wolf who had to be bound by the gods because of his strength and his viciousness. A chain formed with several occult ingredients was used to enslave Fenrir. He will not be released until Ragnarok. On the day of Ragnarok, he will unleash himself and will apparently swallow Odin.

Sleipnir

Now, this has to be one of the most interesting twists in the whole scenario. He is the eight-legged horse that is consistently ridden by Odin when he is riding the nine realms. This eight-legged horse was the son of Loki and Svaldivari. This time Loki shape-shifted himself into a female horse and was impregenated by Svaldivari. He gave birth to his child himself. The eight-legged horse is ridden and is mostly prefered by Odin when riding to Hel.