How I Met Your Mother SPOILERS: The Office's Ellie Kemper Joins Season 9, Guest At Barney, Robin's Wedding

The guest star list for Season 9 of "How I Met Your Mother" continues to grow.

TVLine posted an exclusive report Tuesday that Ellie Kemper of "The Office" and Bridesmaids fame will guest star in an episode of the show's upcoming ninth and final season. Kemper will play a guest named Cassie at Barney and Robin's wedding.

Series co-creators Carter Bays and Craig Thomas told TVLine that Cassie is ""one of the most attractive, available, and - as Ted discovers - unfortunate guests at Barney and Robin's wedding."

Kemper is, at the moment, only scheduled for one episode.

MStars previously reported that the cast and crew had been tweeting some photos from the set, which can be seen here.

Here's everything else that has come out so far about the final season of "How I Met Your Mother":

- Episode 1 will be called "The Locket," Episode 2 will be called "Coming Back" and Episode 3 will be called "The Broken Code."

- The premiere on Monday, Sept. 23 will be an hour long.

- Milioti, who was revealed as the titular Mother at the end of the Season 8 finale, will be a series regular in Season 9.

- Each of the main cast members will meet her throughout the season and Ted will meet her last.

- The entirety of Season 9 will take place during Barney and Robin's wedding weekend, for which the characters departed in the Season 8 finale.

- Season 9 will feature time jumps, flashbacks and flashforwards.