Barry Kripke, Ph.D. is a Caltech plasma-physicist-turned-string-theorist and an unlikable colleague of Leonard and Sheldon. He has a case of rhotacism, where he pronounces "r" and "l" as "w". With a knack for ribbing people, he is an on-and-off friend to Sheldon, Leonard, Howard, and Rajesh.
Despite being a stereotypical geek, Barry apparently tries to be fairly sporty, as shown in "The Friendship Algorithm". In that episode, it was implied that he enjoys polo, water polo, and rock-climbing. "The Rothman Disintegration" reveals that Kripke and Sheldon are "equally bad" at sports. Unlike his colleague, Kripke is fully aware of his limitations and shortcomings, even admitting that he is "creepy, pathetic and can't get girls". He has been known to make inappropriate comments to women, photograph his own gentials and upload the shots to the Internet ("The Beta Test Initiation"), and enjoys hanging out at a strip club near his apartment, which has a free buffet ("The Rothman Disintegration"). He also seems to enjoy strippers.
Kripke is often suggested to be coasting in his job -- in one instance he even goes as far to say that "[he] says [he]'ll prove something that can't be proved [string theory], then use the money for 'wiquow and bwoads' [liquorand broads]". In other instances he engages in robot fighting and makes numerous allusions to his promiscuity (though he appears mostly romantically unsuccessful). On the other hand, in "The Cooper/Kripke Inversion", Sheldon admits Kripke's grant proposal for a fusion reactor for the university is "leaps and bounds" ahead of his [Sheldon's] own. This suggests that Kripke is quite capable -- despite Leonard not believing Kripke to be smarter than Sheldon, Kripke is apparently able to work at Sheldon's level. This may be the reason for Kripke's success in retaining his job despite his apparent predilection for coasting.
Barry Kripke is an slender man with fair skin, brown hair and matching eyes. He wears different types of clothing such as t-shirts, jeans and a jacket in various colors.