He’s played Gandalf, Magneto and Cogsworth but could a child psychologist attempting to deal with Stewie Griffin be Ian McKellen’s toughest role yet?

The award-winning actor will appear in an episode of Family Guy as child psychologist Dr Pritchfield who meets Stewie when the youngster misbehaves at school.

The show’s executive producer Alex Sulkin told Entertainment Weekly the cameo came about through a mutual acquaintance, “one of our writers, Gary Janetti, who wrote the episode, also wrote the BBC series Vicious that starred… Sir Ian McKellen. That’s how we were lucky enough to get him.”

McKellen’s episode is slated to air next spring.