Rapunzel and Yeti were on a superhero team together called The First Line.
Rapunzel's shiny hair could calm down the easily outraged savage Yeti.
Yeti ultimately left the team in disgrace after events referred to as "The Rapunzel Tragedy". No one knows what actually happened, but it doesn't sound good.
He went into hiding in the Himalayas... until one day...
"Korya, a female Skrull agent and an advanced scout for Earth's conquest, approached him, and he told her to go away, as he wanted nothing more to do with the First Line. She told him she was not with the First Line, but that she had traveled a long way to find him. He questioned why anyone would seek out a monster like him. She told him that she didn't see a monster, but rather a lonely soul in need of love and understanding. His attention now hers, she told Yeti that there was much they could do to help each other. "Please...let me be your friend...! Yeti quickly fell in love with the Korya, who convinced him to aid her in the planned Skrull invasion of Earth. Yeti joined Korya aboard the Skrull fleet. As the Skrull fleet prepared its invasion, the First Line boarded one of the ships. Yeti stood beside Korya, who was slain under unspecified circumstances. Her body was discovered by the time-traveling Cassandra Locke, and Yeti found her and swatted her away from Korya, breaking Cassandra's ribs in the process. Yeti took Korya to an escape pod and fled back to Earth with her, thus escaping the destruction of the entire fleet."
"Over time, Korya succeeded in winning Yeti's trust, even making him fall in love with her to the point he became obsessed with her. Willing to do anything for his lover, Yeti betrayed his former teammates. Yeti, spurred on by Korya, was presumably pivotal in an unrevealed incident involving the First Line that would become known throughout the centuries the Rapunzel Tragedy. All the while, Korya kept reporting back to her superiors, assuring them the invasion could proceed according to plan. When the armada approached Earth, Korya took Yeti with her to the flagship of the fleet. Some time later, the First Line attacked the fleet and Korya was fatally wounded under unrevealed circumstances."