Later seasons unveil his tragic backstory, revealing he was once a good human named Simon Petrikov who lost his mind, memories and loved ones due to the magic crown giving him his ice powers. In "Come Along With Me," Ice King is permanently reverted back to Simon after almost being digested by GOLB.
In the Adventure Time finale, she helps summon an evil deity known as GOLB to the Land of Ooo. The Ice King tries to talk her out of her plan, which leads to him, Betty, and Finn all being swallowed by GOLB. Once inside, their powers are absorbed by the deity, causing the Ice King to become Simon again.
Initially, the crown had an addictive effect that created a desire to wear it. However, the danger of using the crown and the subsequent powers it bestows is evident when Simon became more and more "weird" after each successive use until he became the Ice King.
Despite wanting to live a normal life, Ice King's awkward and harmful behaviors drive away friends and potential romantic partners. It is later revealed that wearing the crown drove him insane, and caused him to lose all memories of his past life as a kind man named Simon Petrikov.
In the series finale, "Come Along With Me," Betty is consumed by GOLB with Ice King and Finn. She and Simon are reverted to their original human forms from the deity's "digestive" process.
How Did Simon Become The Winter King? - Adventure Time: Fionna & Cake
Why is Finn the only human?
Finn was, for a long time, the only confirmed human in the Land of Ooo, to the point where he had an epithet, "The Human", and was referred to by many as "Finn the Human". The reason for this is revealed in the episode "Her Parents," as Lady Rainicorn's dad believed that humans were extinct.
Finn seeing Ice King as Simon suggests that Finn feels empathy for what happened to Simon. Additionally, he comments that it's "kind of hard not to" see Simon in Ice King.
According to legend, Night's King was originally a Lord Commander of the Night's Watch who found in the Haunted Forest a cold woman with bright blue eyes, seemingly a female White Walker.
Betty Grof. Betty Grof was a human woman revealed to have once been the fiancée of Simon Petrikov, who would much later become Ice King. She and Petrikov had a very committed relationship until Petrikov obtained an enchanted crown, which gradually began to alter his mind and body.
Relationships. Simon was engaged to Betty Grof, who left him after the crown began to affect his mental health. The loss of Betty, whom he nicknamed "his princess," led to the Ice King's obsession with kidnapping princesses.
Later seasons unveil his tragic backstory, revealing he was once a good human named Simon Petrikov who lost his mind, memories and loved ones due to the magic crown giving him his ice powers which was seen in the episode "Holly Jolly Secrets".
Ice King's desire for “princesses” stems from half-remembered echoes of Simon's old girlfriend, Betty. Even his insanity was a conscious decision, a sacrifice he made after putting on the crown to save a young Marceline.
In "Come Along With Me" Betty Manages to summon GOLB but then gets swallowed by him along with Ice King and Finn. Within GOLB's stomach Simon and Betty return to normal and have a loving reunion together. In the end Betty sacrifices herself to save Simon and banish GOLB by using the crown to merge with GOLB.
Simon, an antiquarian, explains that he bought a magical crown and, after placing it on his head, began to succumb to the crown's power, losing his sanity and his "princess" Betty. Finn and Jake realize that Simon is the same person as the Ice King, and the two take pity on him.
Exactly why The Night King insists on killing Bran is later summed up by the Three-Eyed Raven himself in season 8, episode 2, "A Knight Of The Seven Kingdoms," by stating “He wants to erase this world, and I am its memory.” Since the Three-Eyed Raven is basically a living record of mankind within the world of Game Of ...
So, when Jon saved Commander Jeor Mormont from a Wight, using his bare hand to throw a lantern across the room—he let out a scream. He was burned by the fire; he is not fireproof.
Even during the Age of Heroes, the Night's Queen bore no children for the mysterious 13th Lord Commander of the Night's Watch. As for why babies, and not adults, are candidates for transformation into White Walkers, this is likely because infants are easier to mold into whatever the Night King wishes.
Simon Petrikov was kept alive by the magic of his crown, as he states in his note to Marceline in "I Remember You". Moe kept himself alive through the use of technology and artificial organs, most notably one meant to preserve his memory.
Prior to the start of Adventure Time, Finn was adopted as an infant by two anthropomorphic dogs named Joshua and Margaret, who found him in the woods. His best friend and adoptive brother Jake the Dog (John DiMaggio) accompanies him on many of his adventures in Ooo, the fictional world that the series is set in.
While playing basketball at Marceline's house, Finn and Jake are surprised to learn that Marceline invited the Ice King to play as well. After the two inquire, Marceline reveals that she had known the Ice King when he was still a human man named Simon Petrikov, 996 years before the timeframe of the episode.
Voiced originally by Lena Dunham and later by Felicia Day, Betty was Simon's fiancée 1,000 years before the events of the show. After he found a magic crown and lost his mind, she left him, and they never saw each other again.
The well was said to have magical powers. It was an old rumor, but Simon liked the idea and decided to make a wish. He closed his eyes, made a wish, and tossed the coin. His wish was simple: he wished that someone would knock on his door, and when he'd open, a stray dog would be there.
