There's also 'Batman: Under the Red Hood' which, while not directly about the initial 'Joker kills Robin' event, still touches on the aftermath. It shows how the death of Robin haunts Batman and how it affects the actions of other characters in the Batman universe. It also gives more insight into the Joker's psyche and his role in Robin's death.
The Robin Hood story has its roots in English folklore. It likely emerged from the tales of outlaws who lived in Sherwood Forest. Robin Hood was a heroic figure who robbed from the rich to give to the poor. The 'Red' in 'Red Robin Hood' might be a less common variation perhaps indicating a different aspect of his character or a unique take on the traditional story.
Robin Hood is the main character. He is the heroic outlaw. Then there is Little John, his trusted friend and right - hand man. Maid Marian is also important as Robin Hood's love interest. Friar Tuck, a jovial and kind friar, is another main character who often helps Robin Hood and his men.
The Little Red Robin Hood story often involves a character like Robin Hood who is known for stealing from the rich to give to the poor. In this version perhaps Little Red Robin Hood might be a small and clever hero. He could use his wits and skills to outsmart the wealthy and unjust, and then distribute the goods among the needy in the forest or village.
Probably Little Red Robin Hood himself is the main character. And there could be some villains like the rich lords or the Sheriff - type characters who are against him.
It made the Batman universe much darker. The death of Robin was a huge shock, and it changed Batman's character. He became more brooding and intense. It also showed how dangerous the Joker really was, not just as a villain who commits crimes, but as one who can cause such personal and emotional harm to Batman.
Definitely fiction. Robin Hood's adventures are part of folklore and imagination. There's no historical evidence to prove his existence as depicted in the stories.