The Mad Doctor is the name of the man who processes Thick Blood into stat-augmenting serum. He chiefly does this by operating a machine that seemingly strains the plasma out of the blood; however, it is a somewhat sensitive contraption, as it can only handle so large a volume of the fluid before breaking down, causing the Mad Doctor to attempt to correct the problem, hit it futilely, and then give up, hanging an "Out of Order" sign across it and walking away. (Since Thick Blood does not carry over to the next stage, it is in the player's best interest to reach this breaking point every single time.) The machine's limit does increase each stage, allowing the player to become successively more powerful over the course of the game. The Mad Doctor resides on Channel B. Some players interpret him as yet another iteration, aspect, or owned soul of Harman Smith.