SPOILER ALERT: The Joker is not Robin.
Was a spoiler alert really necessary? Some fans seem to think so!
In the Batman comics universe, Todd succeeds Dick Grayson as Robin. Fans speculated that a tattoo of a dead bird on Leto's Joker's bicep symbolized the character's killing of Jason Todd, which occurs in the Batman comic A Death in the Family.
And then for some strange reason, they thought the killing might be symbolic rather than literal, meaning Todd "killed" his identity as Robin and became the Joker.
It's - a stretch, to say the least.
Suicide Squad director David Ayer seems particularly perplexed by the theory.
He crowned it "the most ridiculous rumour" he saw about the film online and said, "It ain't the case. He's not [Jason Todd]".
Watch Ayer discuss the movie below starting at 2:39. His remarks about the Jason Todd theory start around 3:15.