"The Big Bang Theory" season 9 will air its 200th episode for the hit CBS series.
On Thursday night, the show's 17th episode will focus on Sheldon Cooper's (Jim Parsons) birthday celebration.
Guest stars Wil Wheaton, Sara Gilbert, John Ross Bowie and Christine Baranski will all be present in the said episode, according to TV Guide.
Meanwhile, executive producer Steve Molaro spoke with FOX News to reveal that Batman actor Adam West will also guest star on the show.
According to the exec, it was pretty challenging to get West to agree on appearing on "The Big Bang Theory" season 9.
"We tried last season and came pretty close. We were super excited to get him this year; it's always tricky when actors are playing themselves. But he was incredibly nice and deeply funny. He's pretty comfortable with 'best Batman' comparisons," he said.
In other news, Molaro also dished on what he thinks Sheldon's age on the show is.
In real life, Parsons is 36 years old. However, Molaro said that Sheldon's age might have been vaguely mentioned in the previous episodes, but it was never deliberately declared.
"I don't know his exact age. It's possible it came up and over the course of 200 episodes I don't remember. I'm happy to keep it vaguely in his mid 30s," he said.
Additionally, Molaro also revealed that Sheldon's friends will throw him a party, but it seems that no one will give the character a gift.
"I stood there, looked at the presents, wondering, 'What did they get him?' We'll leave it as a happy mysery!" he said.
Meanwhile, "The Big Bang Theory" has been confirmed to return for season 10.
During a recent interview, Molaro said that he and the writers still don't know what exactly will happen in season 10 because they are still on the process of writing episodes for season 9.
"The Big Bang Theory" also remains to be one of the most popular TV shows on CBS. It stars Kaley Cuoco, Johnny Galecki, Melissa Rauch, Mayim Bialik, Simon Helberg and Kunal Nayyar.
"The Big Bang Theory" season 9 will air on Thursday at 8 p.m. ET on CBS.