Robert De Niro sends presents to Bradley Cooper's dog.

The Hollywood legend became enamoured with Bradley's pet pooch Charlotte on the set of 'Limitless' and can't resist spoiling the dog when he sees something he thinks she would like.

A source said: "He sent the pooch two Pink leather collars and leashes, dog sweaters and treats. Brad was touched."

However, Robert also has a mischievous side and likes playing practical jokes on Bradley whenever he gets the chance.

The source added to National Enquirer magazine: "After finishing 'Limitless', De Niro sent a dozen pizzas to Brad's home with the toppings he hates most - sardines and anchovies."

Robert and Bradley hit it off while working on the movie together and the insider revealed despite the age gap between the 36-year-old Hollywood hunk and the 68-year-old screen veteran, they loved to "get together and eye all the cute actresses and swap war stories about the movies they've made.