Spike Cassidy is an American musician best known as the guitarist for the punk rock band D.R.I. (Dirty Rotten Imbeciles). He co-founded the band in 1982, contributing to their distinctive sound that blends hardcore punk and thrash metal. Cassidy's guitar work is characterized by fast riffs and energetic solos, which have influenced many musicians in the punk and metal scenes. In addition to his work with D.R.I., Cassidy has been involved in various musical projects throughout his career. He is recognized for his dedication to the punk rock genre and has played a significant role in shaping its evolution over the years. His contributions have earned him a respected place in the music community.