Loki

Loki Laufeyson, or Loki Odinson, is the biological son of Laufey, the ruler of the Frost Giants in Jotunheim. Shortly after his birth, Loki was abandoned and left to die. Found by the Asgardian King Odin, he was brought to Asgard and raised by him and his wife Frigga as an Asgardian prince, along with their biological son Thor

When he grew up, him and Thor (alongside friends) went to Jotunheim after they had threatened Odin, To Be Continued.