Tacy Kelly is a fictional character from the popular children's book series, The Magic School Bus, created by Joanna Cole. She is known for her adventurous spirit and curiosity, often exploring various scientific concepts alongside her classmates. Tacy is characterized by her enthusiasm for learning and her ability to think critically about the world around her. In the series, Tacy often participates in the imaginative field trips led by their teacher, Ms. Frizzle. These trips take the students on exciting journeys, such as traveling inside the human body or exploring outer space, allowing them to discover and understand complex scientific ideas in a fun and engaging way.