Professor Pat Pending is a scientist in his Convert-a-Car, a wagon/plane/boat-shaped car equipped with a multitude of gadgets and which can change into just about anything that moves.
Among the things his car has transformed into include a motorcycle, a jetpack, a flying carpet on wheels, a forklift, an arrow, a bicycle built for two, a bowling ball, a basketball, a blimp, a rocket and even an exact duplicate of the Slag Brothers driving the Bouldermobile (when the real Slag Brothers saw this, they cheered their doubles on!). He's sometimes seen as a rival of Dick Dastardly and Muttley, since his car is equipped with a lot of gadgets, just like the Mean Machine, although they are more defensive, or merely speed-boosting, in nature. He often uses his car's gadgets to help out the other drivers if they all get caught in the same trap, such as when he used his car's de-glue gizmo to free everyone from a glue trap left by Dastardly. His alliterative name is a pun on the phrase "patent pending".
Professor Pat Pending was originally voiced by Don Messick, and currently by Scott Innes.