David Tennant's son Wilfred is poised to follow in his dad's footsteps with an illustrious career in film and television, as he has made his acting debut in long-running hospital soap Casualty at just nine years old.The youngster appeared on-screen as an anxious little boy desperate for the doctors to help his pet gerbil. Wearing his blonde hair loose and wavy, the little boy donned a cream ribbed cardigan and glasses as he stole the scene from two of the BBC show's permanent cast members. Wandering into the Holby City hospital clutching a box in his arms, Wilfred took his role as character Joey Parker very seriously, speaking to the doctors about his ill and beloved pet Rory.