Thing 1 is a character from the popular children's book "The Cat in the Hat" by Dr. Seuss. It is one of two mischievous creatures that bring chaos and fun to a rainy day. Thing 1 is known for its bright red hair and playful personality, often causing trouble alongside Thing 2. In the story, Thing 1 and Thing 2 engage in various antics, much to the dismay of the children and their pet fish. Their playful behavior highlights themes of imagination and the importance of responsibility, making Thing 1 a memorable character in children's literature.