Abstract: A drain snake (4) with a ball (8, 42) on a forward end of a cable (6), the ball having a convex leading surface (36) with a protrusion (10, 44) designed to act as a foot that steps over the end (22, 30) of a pipe (24) in an elbow (26) as the snake is rotated (32). In an embodiment, the protrusion may terminate laterally at 60-150% of a maximum lateral extent (R, 37) of the ball or the protrusion may be limited to the lateral extent of the ball. The protrusion may form a rotationally asymmetric surface arrangement on the ball. The protrusion may have a forward cutting edge (48, 53) and may have a lateral cutting edge (52). The cable (6) may be designed to flex laterally while remaining substantially inelastic axially under manual feed and retraction forces.