A clip has been released of Ryan Reynolds making a cameo in the Family Guy Christmas special.

The Green Lantern heartthrob plays the forerunner of Jesus in the episode, which features leading man Peter Griffin and wife Lois as Joseph and Mary.

In clips released ahead of the show airing, Ryan plays the first son of God, who wasn't as clever as his successor.

The Canadian star is also lending his voice to the animated film Turbo, which is currently being made.

Previous celebs who have made guest appearances on Family Guy include Johnny Depp and Drew Barrymore.

The festive episode will air in the US on Sunday.