While mostly appearing in minor roles, Brian Posehn has loads of acting credits to his name. He first started acting in various small roles in the mid-90s and has been in the industry ever since. He’s done film, TV, voice acting and has even produced and written for television.
Among his latest roles, you can find a recurring role in the TV show “Top Secret Videos” and the voice role of Sour Cream in the sophisticated cartoon, “Steven Universe.”
Bob Newhart as Arthur Jeffries — Now
Bib Newhart needs no introduction, but we're going to brave one anyway. With his brilliant example of deadpan comedy, Newhart has been a legend for many decades now. He had his big break in 1960 with "The Button-Down Mind Of Bob Newhart," his album of comedic monologues, and went on to have one of the most prolific careers the comedy world has ever seen.
After his role in "The Big Bang Theory," Newhart went on to reprise his role as Professor Proton (though mostly as a voice-over) in "Young Sheldon," the prequel show, depicting Sheldon's life as a little kid.
Brian Posehn as Bert Kibbler — Then
Bert is another researcher from Caltech — a geologist who enjoys the occasional rock pun, as his profession requires. In season 7, Bert expresses some interest in Amy, who remains oblivious until told about it by her friends.
We wouldn't worry about Bert's fate, though. He later turns out as a pretty sweet guy with a pretty cool job, and he even gets a fancy research grant most of the gang can only dream of.
Judd Hirsch as Alfred Hofstadter — Then
Although mentioned many times over the course of the show, Alfred Hofstadter, Leonard's father, appears in the flesh for no more than two episodes. Before that, all the things the viewers knew about him were bits of information told by Leonard's mother, Beverly, which didn't paint him in a very flattering light.
However, the two eventually get divorced, which benefits them both. In fact, at the end of season 9, he meets Mary, Sheldon's mother, and the two seem to have good chemistry, which leads to a prospect of an interesting relationship.
Judd Hirsch as Alfred Hofstadter — Now
Judd Hirsch's impressive acting career stretches all the way back to the early 1970s! He started with a couple of tiny, uncredited roles and steadily climbed the ranks until getting his most memorable role as Alex Reiger in the TV show "Taxi," which ran for more than 100 episodes.
TBBT was a drop in the bucket of acting credits this actor has under his belt. After the show ended, he never went off screen and kept appearing regularly n a multitude of TV productions, and has even lent his voice to the Netflix hit adult cartoon "Big Mouth."