Alyson Hannigan will be making a return to the network that made her a sitcom star in 'How I Met Your Mother' as she has landed a guest-starring role in CBS's newest comedy 'The McCarthys,' set to air in December.

Alyson Hannigan
Hannigan will return to CBS for a guest appearance in 'The McCarthys'

The new series, which premiered October 30th, follows a very close Irish-Catholic family based in Boston, who sports-obsessed, but tensions arise when the patriarch takes his athletically challenged, and openly gay, son Ronny (Tyler Ritter) under his wing.

The network announced on Friday (Nov 14th) that Hannigan, who portrayed Lily Aldrin on the long-running CBS sitcom, will star in a Christmas-themed episode as Pam - Marjorie (Laurie Metcalf) and Arthur's (Jack McGee) sweet tenant who was recently left broken-hearted.

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In an effort to cheer her up, the Boston family invite Pam to join them for dinner on Christmas Eve, but she is left rather shocked after witnessing how ruthless The McCarthys become when playing their annual gift-exchange swap.

This will be the first television role for Hannigan since wrapping up filming of the ninth and last season of 'How I Met Your Mother' earlier this year. She was previously expected to star in a pilot of the CBS comedy 'More Time With Family,' but the network did not move forward with this.

As well as starring in 'HIMYM,' the 40 year-old actress is known for playing Willow in 'Buffy the Vampire Slayer,' and her role as Michelle in the 'American Pie' movies.

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Hannigan's guest appearance is set to air on Thursday, Dec. 18.