Friday in Crusoe was a creature with self-awareness and independent thinking ability. Different from other animals, he had a high degree of intelligence and language ability. In the novel, Friday was originally Crusoe's pet, but in an accident, Friday was drifted to an isolated island by the waves. Crusoe was forced to live on the island for 28 years. Friday spent a long time on the island and gradually established a deep relationship with Crusoe. Friday learned many survival skills on the island, including cooking, making tools, and building houses. He also learned to read and understand human language and was able to communicate effectively with Crusoe. In the end, after spending 28 years of loneliness on the island, Crusoe returned safely to human society on Friday and became an independent, intelligent, and caring human.