As Bollywood superstar, Akshay Kumar turned 51 today, he had a special treat in store for fans- a fresh poster of his upcoming sci-fi film '2.0' starring Rajnikanth.

Writing how the character of a dark superhero has been the most powerful for him, the 'Gold' star revealed the poster showcasing his menacing avatar.

"Here's a special birthday treat for all my fans. Sharing with you my most powerful character & one which has probably stayed with me for the longest time. I am the dark superhero for those who don't have a voice! HUMANS BEWARE!" read the caption.

Directed by S. Shankar, the film also stars Amy Jackson, who plays a droid.

'2.0', which brings Rajinikanth, Akshay Kumar, and Director Shankar together for the first time, is a sequel of 2010 film 'Enthiran' (released in Hindi as 'Robot'), in which Akshay will play the role of an antagonist, a scientist who becomes eccentric after an experiment goes wrong.

The flick will hit the silver screens on November 29 this year.