Taika Waititi's crack up birthday message for Iron Man Robert Downey Jr.

Kiwi filmmaker Taika Waititi has sent Hollywood star Robert Downey Jr a birthday message while appearing to mistake the Avengers: Endgame star for Graham Norton.

The Oscar-winning director of Jojo Rabbit showed off his weird sense of humour yesterday, when he jokingly posted a photo of the British talk show host on social media, while wishing Downey Jr, who turned 55 yesterday, a "happy birthday".

The typically off-beat post was liked by more than 160,000 of Waititi's followers while it also won the approval of fellow Marvel movie star Jake Gyllenhaal, who replied to the message on Instagram with a couple of crying laughter emoji's.

Waititi's tribute left some fans scratching their heads however, as two followers on Twitter replied with: "He looked so different here wowee" and "your mind works in ways ill never understand".

Others commented that Norton would probably enjoy the comparison, tweeting: "Graham Norton is going to love this".

Meanwhile, Downey Jr marked his birthday by heaping praise on the frontline workers amidst the coronavirus pandemic.

The Iron Man star used his big day to pledge support and his gratitude to those working hard to keep the world safe amidst the virus, which has claimed the lives of thousands of people worldwide.

He wrote on Instagram: "'If u don't like something, change it. If you can't change it, change your attitude...' #mayaangelou #happybirthday #Poet #Activist 1928-2014 It's an honour to share a birthday with this great #woman, and a necessity to express my #gratitude to the following - #Healthcare workers, Personal care and home health aides, First responders, Anyone in an active service job, As well as law enforcement, the National Guard, all Armed Services, etc ... Anyone braving exposure in the #service of others - Proudly, RDJ (sic)"

Downey's friends and co-stars rushed to social media to send their birthday wishes, with Chris Evans writing on Twitter: "Happy birthday to one of my absolute favorites! Love you 3000, @RobertDowneyJr (sic)"

Gwyneth Paltrow shared: "Before we put this day to bed, I must wish my dear, dear @robertdowneyjr a happy birthday. Here he is, making a toast at our wedding, during which his humour elicited my usual look of pure joy/shock whenever he is near. He is my brother, friend and supporter. A mega genius, and the weirdest comedy writer of all time.

"I know all of our @marvel family join me in wishing him a very happy day. Do you love Robert? Let him hear you if you do. We love you RDJ (sic)"

Mark Ruffalo wrote: "Sending you all the virtual hugs for your birthday, @RobertDowneyJr ... I love you to life, 3000. It's an honour knowing such a generous and complex man. (sic)"

- with Bang Showbiz