1) Fictional businessperson 2) Honcho 3) Important person 4) Slang for an important person 
[tricycle] A Big Wheel is a type of tricycle, usually made of plastic, with an oversized front wheel, that rides very low to the ground. Introduced by Louis Marx and Company in 1969 and manufactured in Erie, Pennsylvania, the Big Wheel was a very popular toy in the 1970s in the United States, partly because of its low cost and partly becaus...
Big wheel is slang for an important person.
an influential or important person: a big wheel in business.