'How I Met Your Mother' Season Finale: Mother Revealed! (SPOILERS)

"How I Met Your Mother" fans are celebrating the long-awaited reveal of "the mother" on the season finale Monday night.

Throughout all eight seasons of CBS' hit television series, the narrator and lead character Ted Mosby explained to his children, and viewers, the story behind how he had met their mother.

However, it took all eight seasons and over 300 episodes for the unveiling of the mother.

"HIMYM," which stars Neil Patrick Harris, Jason Segel, and many more, is filmed in a series of flashbacks of Ted (Josh Radnor) and his friends in New York City.

As the series prepares to close Monday with its next and final ninth season, the last episode of season eight revealed actress Cristin Milioti in a brief scene.

Recognized immediately for the yellow umbrella she was holding, the show's title character appeared at the very end of Monday's episode buying a train ticket.

While little else is known about the character, it is understood that she will attend the wedding of Barney and Robin, where she will meet her future husband, Ted, and play a large role in the upcoming and final ninth season of the series.

Although fans have many unanswered questions about Milioti's character, there is information about the actress herself.

The 27-year-old actress who landed the long-awaited role hails from Cherry Hill, N.J. and is best known for her lead role on the award-winning Broadway show "Once."

Furthermore, Milioti has made an appearance on "30 Rock" as well as in Martin Scorsese's "The Wolf on Wall Street" where she portrays the first wife of Leonardo DiCaprio's character.

As for the actress' debut on "HIMYM" Monday night, fans were abuzz on social media sites hours after the character reveal.

"Is it too early to say but this is the 2nd best thing to happen on TV ever #wemetthemother #himym," wrote Sabrina.

Haan added, "After 8 long seasons, the wait is finally over. They have finally revealed the mother in HIMYM. My life is complete."

Season nine of "HIMYM" will begin on CBS this fall.