"The Big Bang Theory" is set to hit another milestone as it celebrates its 200^th episode. Episode 17 of season 9 will treat fans to an hour of excitement as some old cast members and another guest star roll up to join the party.

Entitled "The Celebration Experimentation," the episode will bring the gang together to attend Sheldon's (Jim Parsons) birthday party, with former characters Dr. Beverly Hofstadter (Christine Baranski), Barry Kripke (John Ross Bowie), Leslie Winkle (Sara Gilbert) and Wil Wheaton making special appearances at the show.

The long-running sitcom is keeping most of the details of its landmark episode under wraps and it is still unknown as to how the guest stars will pop in the scene, but the promotional photo of the show teased that acting legend Adam West will also grace the revelry as Sheldon's friends' major birthday surprise for him.

His appearance is expected to be a showstopper, as he will not only be portrayed as Sheldon's heroic idol but Leonard's (Johnny Galecki), Howard's (Simon Helberg) and Raj's (Kundal Nayyar) as well.

In a teaser released by Entertainment Weekly, West will play the role of Sheldon's favorite superhero actor, whose character has been mentioned many times in the previous episodes of the sitcom. It can be remembered that Sheldon impersonated West in the third season, following Penny's (Kaley Cuoco) revelation that she did now know West. In the fourth season, Howard also dressed up like Batman, Bruce Wayne's alter ego.

87-year-old Adam West rose to fame after starring in the hit ABC campy live-action series "Batman," which ran from 1966 to 1968.

 "The Celebration Experimentation" will air on February 25, 8:00 p.m. ET on CBS.