Acting veteran John Hurt and British comedian David Walliams have loaned their voices to a U.K. advertising campaign instructing parents how to save a choking child.

The Alien star and the funnyman, plus comedians David Mitchell and Johnny Vegas, voice the animated commercial for the U.K.'s leading first aid charity St. John Ambulance.

The stars play 'The Chokeables', a variety of objects that a child could accidentally swallow, such as a pen lid and a marble. Hurt voices a peanut and Walliams is a small doll, and they tell parents what steps to take if their baby is choking.