1) Big shot 2) Bigwig 3) Kahuna 4) Something important 1) Vip 
This is unusual. A biggie is what a child calls his poo! Hence the reason Wendy's Hamburgers has never really taken off in England
an important, influential, or prominent person; big shot; bigwig. · something that is very large, important, impressive, or successful: a merger of two corporate biggies; a movie that was this year's box-office biggie.