"Lassie" is a fictional character, a Rough Collie dog, created by author Eric Knight. The character first appeared in a short story published in 1938 and later in a novel. Lassie is known for her intelligence, loyalty, and bravery, often helping her young owner, Timmy, in various adventures and emergencies. The popularity of Lassie led to numerous adaptations, including films, television series, and merchandise. The most famous television show aired from 1954 to 1973, showcasing Lassie's heroic deeds and her strong bond with Timmy and his family. The character has become an enduring symbol of loyalty and friendship.