She was the first born in Viper's family. She had very much potential to her father as well as having very beautiful fangs, and quickness to learn Kung-Fu. She did, however, have a flaw; She was very trouble making. She would more or so cause mayhem and take something that didn't belong to her. But what destroyed her bonds with the family forever is that she assaulted Master Oogway, who tried to reason with her about her choice in life. She failed, and Oogway used his Kung-Fu to shatter her fangs forever. Oogway sentenced her to wear The Black Mask of Shame (As portrayed in this picture). By the time Viper was born, Sing Jin was finally kicked out by her enraged father, with her mother being too upset of losing her daughter and loyal to her husband to do a darn thing about it to stop it. Sing Jin was heart broken, and left the Valley of Peace to wonder the world, and start a new life if she can. She came across Dr. Facilier, who offered to help her to find a new home in exchange to one day serve the League on the day of his choosing. She agreed, and Facilier had her join the Guild of China's Worse, a guild of really talented thieves. However, Sing Jin was still depressed about never getting the chance to see her sister grow up to lead the right path, and hopes to one day rejoin her and her noble cause, and put her talents to a proper use. Little does she realize that that day may come soon enough, sooner then she believes.
- "I hate my life!"
- "Oh, Viper! If only I could see you right now, I'd be a lot happier."
- "This mask is itchy."