A snake tool adaptor capable of coupling commercially available heavy duty drain cleaning cables and attachments normally associated with heavy electric drain cleaners with a portable rotary driving tool such as a hand-held drill. Adaptors of the subject invention include a hand grip having a proximal end terminating in a shank for operable attachment to a the chuck of a power drill, and a distal end terminating in coupling means for removable mating engagement with various heavy duty drain cleaning cables and their attachments normally associated with heavy electric drain cleaners.