'HIMYM' Alum Alyson Hannigan To Guest Star In New Christmas Episode For 'The McCarthys'

How I Met Your Mother star Alyson Hannigan is making her way back to television — well, sort of. The 40-year-old actress is coming to TV as a guest star on CBS' new series The McCarthys.

Buffy the Vampire Slayer and HIMYM fans are getting an early Christmas gift in the form of Alyson being back on TV ... even if it's only as a guest role for one night. According to TV Line, Alyson has officially signed on to guest star on CBS' newest Thursday night comedy.

The McCarthys is a new show for CBS about an Irish-Catholic family that live in Boston in a three-story house all together. The show follows the sports-crazed family and the one family member that makes a big change by moving out on his own. The series premiered on Oct. 30.

The Christmas-themed episode will star Alyson as Pam, Marjorie McCarthy (played by Laurie Metcalf) and Arthur McCarthy's (played by Jack McGee) upstairs neighbor. According to Entertainment Weekly Pam is described as "sweet, but fresh from a break-up and broken-hearted."

"In order to cheer her up, Marjorie invites Pam to join the family for Christmas Eve, however, as Pam watches the McCarthys play their very competitive annual gift-exchange swap, she is shocked by how the family treats each other," TV Line explained.

The mother-of-two is best known for her roles as Willow Rosenberg in Buffy the Vampire Slayer, Lily Aldrin in How I Met Your Mother and Michelle Flaherty in the American Pie films. Through this venture Alyson will also be reuniting with HIMYM's director Pam Fryman who is the executive producer and director on The McCarthys.

The series also stars Joey McIntyre as Gerard McCarthy, Jimmy Dunn as Sean McCarthy, Tyler Ritter as Ronny McCarthy and Kelen Coleman as Jackie McCarthy.

Check out The McCarthys trailer below.