Robin Hood was the name given to a fictional character from Human mythology who was the leader of a band of Merry Men in an area of England known as Sherwood Forest. According to legend, Hood and his men robbed from the rich to give to the poor, while staying one step ahead of their arch-enemy, the Sheriff of Nottingham. Hood was arguably most famous for his courageous rescue of his beloved Maid Marian from Nottingham Castle.
In 2367, Q transported the senior officers of the USS Enterprise-D into a recreation of Sherwood Forest and made the senior staff assume the role of Hood and his Merry Men. The role of Hood was played by Captain Jean-Luc Picard who had to choose to rescue Maid Marian (whose role had been taken by Vash) at risk to his crew, or to let Marian die and keep his crew safe. Eventually, Picard decided to rescue Vash and his crew launched an attack on the castle. (TNG episode: "Qpid")
When the purpose of Q's continual visits to the Enterprise and Picard was revealed in 2380, Picard asked Q what the purpose of their experience in Sherwood Forest was. Q replied that he "just wanted to see you in tights, Jean-Luc". (TNG novel: Q & A)