Cirno's catchphrase in doujin works, "I'm the strongest!", comes from her dialogue in PoFV, in which she announces this in her scenario, while being everyone else's stage one boss. She also says it when winning against herself in Phantasmagoria of Flower View and in Hisoutensoku.
Because of this, some people tend to call her "the self-proclaimed Chuck Norris" of Touhou.
Despite not appearing in most Touhou games, Cirno is one of the most popular characters mainly due to fandom making references to her in non-related topics.
She is shown often with a form with control over fire.