The dashing and debonair Hollywood star, who won our hearts with his portrayal of Tony Stark in Iron Man and that of Sherlock Holmes, turns 54 today. On the occasion of Robert Downey Jr's birthday, we bring you a list of 10 interesting facts about the flamboyant actor that you may not have known.

1. Robert Downey Jr. made his debut as an actor at the age of five in the film 'Pound' (1970), written and directed by his father, Robert Downey Sr. He played a sick puppy in this absurdist comedy about several dogs (played by humans) waiting at a pound (animal shelter) to be put to sleep.