William Spencer (ウィリアムスペンサー) competed on the first American Ninja Warrior competition. In the Qualifying Round, he got the fastest time of 33 seconds and went last in the semi-finals. There, he again got the fastest time, 1:23 seconds. In the finals, he got second in his group behind Levi Meeuwenberg. However, collapsed due to heat exhaustion after the first challenge, was unable to continue and subsequently disqualified.

He also competed on the second competition and completed the qualifying round in 8th place. But in the Semi Finals he failed the Salmon Ladder.

It's Effin' Science

One year after his first ANW attempt. William made an appearance on the new G4 TV show. It's Effin' Science. He was a demonstrator for a science experiment called the rocket skateboard. He was to ride it up a ramp and land it (albeit bailing due to the speed of the board).