Professor Crawley is a bitter entomologist at the California Institute of Technology. He was portrayed by well-known stand-up comedian and writer Lewis Black, whose brand of comedy consists of angry rants about history, politics, religion, trends and cultural phenomena.
Professor Crawley mentions that he has studied insects since he was eight years old, earning him the school nickname "Creepy Crawley". He has twenty years of experience and a doctorate. He is divorced after his wife cheated on him with "a two-bit ornithologist who lives on a sailboat and likes to wear boot-cut jeans" while he was in the Bornean rainforest and discovered a new species of dung beetle.
In "The Jiminy Conjecture", Caltech has cut off the funding for his lab, forcing him to move in with his daughter in Oxnard, California. In the same episode, Sheldon and Howard ask him to identify the species of a cricket they caught in order to settle a bet.
- The name Crawley is a pun on the way insects get around by crawling along the ground.