Kunal Nayyar stars as Rajesh Koothrappali, an Astrophysicist that works with Sheldon and Leonard at Caltech. He is best friends with Wolowitz and lives in an apartment by himself.  Rajeesh is from India and communicates with his parents back at home via video conferencing software.

Rajeesh is a bit of a celebrity after he was named in People's "30 Under 30."  Rajeesh has major social anxiety and can only talk to women under the influence of alcohol.

Rajesh "Raj" Koothrappali Quotes

Leonard: Hi. I'm Leonard. You are beautiful. You pop, sparkle and buzz electric. I'm going to pick you up at eight, show you a night you will never forget.
Raj: Where are we going?

Sheldon: I recently read that during World War Two, Joseph Stalin had a research program to create supersoldiers by having women impregnated by gorillas.
Howard: What a sick use of science.
Raj: Hey, as long as the baby's healthy.
Amy: I wonder if Stalin considered any other animals.
Leonard: Hippos are the deadliest creature. A half-human, half-hippo soldier would be pretty badass.
Howard: Yes, but when they're hungry-hungry, you can stop them with marbles.
Sheldon: Yeah, the correct animal for interspecies supersolider is koala. You would wind up with an army so cute it couldn't be attacked.

TBBT Quotes

Penny, there's only one cookie with something in the middle that solves life's problems, and that's an Oreo. Or a Nutter Butter, if you're in a pinch.

Sheldon

Penny: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny, get your own Wi-Fi." No spaces.