Doc Hump was originally sent for by Larceny Lu to treat Steve the Tramp but was subdued and bound by Scotty Bumpstead who took his place. Lu recognized Scotty and captured him and gave him to Doc Hump. Doc Hump was about to experiment on Scotty when one of Lu’s men unwittingly lit Scotty’s cigar/smoke bomb, leading to the two men’s arrests.
Later Doc Hump was freed from jail and he went to his family mansion where he injected dogs with rabies and planned to kill Tracy with them. Doc went to test them on his butler, but Tracy showed up on time and rescued him. Doc Hump went to unleash another dog on Tracy, but when it sensed that Hump was the true enemy, it tore his throat out instead.