Superstar Amitabh Bachchan has gone grey and haggard for R Balki’s Shamitabh.He was spotted sporting grey, dis-shelved hair and long, thick beard at Mumbai Lokhandwala Gardens last week during a shoot of the film.Amitabh Bachchan shhoting for Shamitabh. Pic courtesy: TwitterSome time ago the actor had tweeted, “An arduous sitting for Balki’s (Balakrishnan) look test with the lovely Dominie from L.A. that did my prosthetic make-up for ‘Paa’,” Amitabh posted on Twitter.”It took time to be accomplished – the make-up I mean. It’s 3:30 am! What? Off to bed,” he further posted.Amitabh has earlier worked with R Balki in Cheeni Kum and Paa where he sported distinct looks. A pony tail in Cheeni Kum and prosthetic make-up in Paa.The film also features Raanjhanaa star Dhanush and southern star Kamal Haasan’s younger daughter Akshara.