'Avatar' director James Cameron has congratulated 'Avengers: Endgame' makers after it surpassed the record of 'Avatar' to become the highest-grossing film of all time. "Congratulations to Avengers: Endgame on becoming the new box-office king," the text accompanying a picture of Iron Man with Pandora's creatures read. Cameron also congratulated Marvel when it broke the record of his other film 'Titanic'.