Dan Gregor is an American comedian, writer and producer. He is a native of Long Island, New York and was raised in a conservative Jewish home. At New York University he became a founding member of the award winning sketch group "Hammerkatz". He wrote and produced online shorts with his comedy troupe and later performed improv with the Upright Citizens Brigade theater. Gregor formed a production company called Chubby Kinney Kids with his writing partners Doug Mand and Adam Pally. They began writing various television pilots some of which were based on his stage shows inspired by his dating life in New York. These got him noticed by producers of the CBS sitcom "How I Met Your Mother" who hired him alongside Doug Mand. Together they worked on the series from 2011 to 2013. Around this time he began a relationship with comedian Rachel Bloom and after a six year courtship they were married in 2015. Gregor, along with Doug Mand, is currently a writer on The CW network show "Crazy Ex-Girlfriend" which was co-created by his wife and Aline Brosh McKenna. He also appeared onscreen twice on the show as the character Dr. Nick Roth and Dr. Chester Roth.