The racer ("Coluber constrictor") is a species of non-venomous colubrid snake. The eastern racer ("Coluber constrictor") is a species of nonvenomous snake in the family Colubridae. The eastern racer ("Coluber constrictor") is a species of non-venomous, colubrid snakes. The eastern racer ("Coluber constrictor") is a species of non-venomous, colubrid snake. "Coluber constrictor flaviventris" is listed as an endangered species in the province of Saskatchewan.