David Lynn Thomas (born 1953) is an American singer, songwriter and musician, now based in the UK. He was one of the founding members of the short-lived proto-punkers Rocket from the Tombs (1974–1975), in which he played under the moniker "Crocus Behemoth," and of post-punk group Pere Ubu (1975–present, intermittently). He has also released several solo albums. Though primarily a singer, he sometimes plays melodeon, trombone, musette, guitar or other instruments.

Thomas has a distinctive, high pitched voice; Emerson Dameron described Thomas's singing as "James Stewart trapped in an oboe", and Greil Marcus writes, "Mr Thomas's voice is that of a man muttering in a crowd. You think he's talking to himself until you realize he's talking to you."