Bill Nighy as Philip, turning into a zombie in Shaun of The Dead
A man decides to turn his moribund life around by winning back his ex-girlfriend, reconciling his relationship with his mother and dealing with an entire community that has returned from the dead to eat the living. (from IMDB)
From the website:
Bill plays Philip. Philip is that most feared of filial figures, the stepfather. He is an interloper, a stranger, an enemy of the son that has stepped in and stolen that most precious of loved objects: mummy. However there is more to Philip than Shaun might blindly affirm. There are motives behind his severity that come from deeper places and fate is poised to show Shaun that Philip might not be a monster after all. Then again…
But the real stars are his mum, the magnificent Penelope Wilton, and stepdad, Bill Nighy, who move the splatter farce into more resonant areas.