- "Just because I look like Niklaus doesn't mean I am him. I do have my own personality you know."
- —Sandy trying to clear up the fact that he isn't like his twin
Sandy was born to Esther Mikaelson and a werewolf, Lucius Kaylock in a small village that is eventually known as Mystic Falls. He is also the younger twin brother to Niklaus Mikaelson.
Unlike his elder brother, Sandy is not a part of the Mikaelson family. Due to Sandy being born silent, but alive, Esther had thought that he had been born dead thus making a decision to just return home with Niklaus. Esther had given birth to the twins at the Kaylock household, but had explained to her husband Mikael, that she had given birth to them at a friend's house. Sandy was left with her werewolf lover, Lucius and his son Charlie. Esther was never told that Sandy was still alive and Lucius decided to keep it that way. Klaus was also unaware that he had a twin brother.
Sandy had the same upbringing as Charlie did. There was nothing out of the ordinary with the way that Sandy was raised although by the time that Lucius thought that Sandy was old enough, his father began teaching Sandy how to defend himself. Lucius stopped his affair's with the woman of the neighbouring town and kept his mind set on raising his two sons.
None of the Kaylock's could figure out what happened, but Sandy had changed. Although he was still a werewolf, he had also become a vampire as well. Due to Esther having performed a spell after her youngest son, Henrik was killed, she hadn't realised that it wasn't just her family that she was with would be effected by it. As she didn't know that Sandy was still alive, she was unable to know that the spell had also changed him too. After Sandy had made his first kill, everything changed. Soon after, Sandy had watched from outside the house as Mikael Mikaelson killed both Lucius and his elder brother. Unfortunately, Sandy was unable to get away and ended up with the same fate as his father and brother. This ignited a war between both species - werewolves and vampires. Fortunately for Sandy, Mikael had been unable to fully kill him due to being a hybrid. As Esther had placed a curse upon Klaus, unlike the vampire spell, the curse hadn't affected Sandy thus he was able to continue on as a hybrid.
1930 | 1940sEdit
Throughout the years, Sandy had learned to control himself. He refused to kill people just for the simple fact that he didn't like killing people. Even though it was meant to be in his nature of killing humans, it wasn't something he was comfortable with. Up until the 1930's, he had been killing as he went from town to town, but stopped around 1934 after finding out that drinking from blood bags were easier to attain than getting fresh blood from the source.
In 1939, Sandy had met a young woman, Millicent (a.k.a Millie) in Los Angeles. She was a bartender from a small pub, trying to make ends meet when it came to money and also trying to keep her son, Reuben feed. Sandy became friends with Millie as he often stopped by the same small pub every few days. To Sandy, it seemed in a way wrong falling for a human, but it happened and he didn't bother trying to stop it.
As years went by, around 1944, Millie had found out about what species Sandy was, this was only because Sandy chose to tell her. Millie, at first, freaked out, but concluded that she wouldn't stop the relationship due to the simple fact that Sandy had never harmed Millie nor Reuben. The relationship continued and Millie had eventually became Sandy's fiance. For when it came to Reuben, even though he wasn't Sandy's child, Sandy thought of him that way and Reuben seemed to go along with it.
1960 | 1970sEdit
Due to Sandy being able to attain money when he needed it, Millie and Reuben had left their apartment and moved in with Sandy. Throughout his years of life, he enjoyed the years he spent with his fiance and son the most. This didn't last for long. A werewolf with a vengeance had come looking for Sandy. Unfortunately due to Sandy being out at the time, Millie and Reuben had to suffer the consequences instead.
Sandy had returned to the apartment to a blood bath. Millie had been ripped apart, each of her limbs spread out within the rooms and Reuben had been torn to pieces. Sandy was torn inside, barely believing that the two people he loved were killed for his mistakes.
It wasn't until the late 1970s that Sandy had managed to locate Millie and Reuben's killer in New York. Their killers was a young werewolf called Cameron Ball and Sandy had remembered killing his father, Eamon Ball. Sandy had been able to tear apart Cameron before he could even blink. Cameron had saut out Sandy for revenge and Sandy had done the exact same thing.
After killing Cameron, Sandy left New York and headed to the town he was born in, Mystic Falls. He refused point blank to return to Los Angeles due to the fact that he had too many memories of Millie and Reuben. Sandy settled down in Mystic Falls and was well aware of the supernatural species that occupied the town.