Throughout his career so far Gregery has collaborated with clients including Cartoon Network's Adult Swim, Netflix, Hitpoint Games, Disney, Microsoft, This American Life, Wild Turkey Whisky, Free Range Studios and The Wall Street Journal.

In 2019 Gregery completed the Illustration Master Course (IMC2019) under the guidance of leading illustrators in the fantasy realm. In 2016 Gregery was awarded the STARS grant from the Massachusetts Cultural Council where he taught sequential art and animation in Boston Public Schools. Later that year Gregery accepted an Assets for Artists Residency in The Studios at the Massachusetts Museum of Contemporary Art (Mass MoCA) where he was the first artist to ever produce a comic in the program.