Walter Wisdom was "Doc" Emmett Brown's roommate in the American College of Technical Science & Complicated Math. He was the host of the popular kids show Mr. Wisdom and the inventor of such things as the Perpetual Motion Hula Hoop. 
While in college, Walter Wisdom falsely took credit for an invention that he had stolen from Doc, creating a lifelong enmity between the two men. While Doc went on to greater discoveries, "Mr. Wisdom" continued to steal from others and hosted a mediocre "educational" program on television, presenting inaccurate science lessons to children (in one show, he dropped ping pong balls on the ground and explained that atoms worked the same way). His catch phrases were "Put on your thinking caps, kids!" and "Cool enough, neighbors?" Mr. Wisdom took his show on the road during the off-season, and when he stopped in Hill Valley in 1992, he encountered Doc again for the first time in decades. Mr. Wisdom stole the DeLorean time machine and, true to form, claimed credit for inventing it and tried to put it on sale on television. Mr. Wisdom's plans were foiled and he was exposed as a fraud. 
Later in 1992, Mr. Wisdom and Biff Tannen combined to steal a baby dinosaur named Tiny for a live television program. Mr Wisdom wants revenge against Marty and Doc and the rest of the Brown ruining his reputation and his show. Once again, Marty McFly and the Brown family foiled Mr. Wisdom's plan and made him look foolish on television again as a fraud. His show was cancelled for good this time. 
Personality and traits
Oddly enough when not in disguise he sounded a lot like Biff Tannen and had yellow eyes and teeth, the two traits most Tannens all seemed to possess. However it is unknown if there is any connection to Wisdom and the Tannens.
Behind the scenes
- Walter Wisdom was introduced in the second episode of the second season (15th overall) of Back to the Future: The Animated Series, and returned in the very final episode (26th overall, 13th of season 2).
- Back to the Future: The Animated Series