Tracy Strauss, portrayed by Ali Larter, is a fictional character on the NBC science fiction drama series Heroes. She has the ability to freeze anything that she touches. As the series progresses, her ability evolved to include water mimicry. Introduced in the third season, she is an adviser to the governor of New York who recruits Nathan Petrelli as a senator. She is the triplet sister of Niki Sanders and Barbara, all three having been genetically modified by Dr.