Haneef Munir, who competes as Young Hollywood, is a 5'10" dunker with a 50" vertical. He came up through the Team Flight Brothers era, when the touring circuit rather than the internet was how a dunker built a name.
He won the Sprite Slam Dunk Showdown in 2011, which at the time was the largest amateur dunk competition in the United States and the event that decided who the country considered its best unsigned dunker that year. The Showdown ran through regional qualifiers into a national final at NBA All-Star Weekend, so winning it meant beating a field assembled from every city that held a leg.
The clip most people know came at a Jordan Brand event outside the Nike store in Santa Monica Place. Blake Griffin, who was then the reigning NBA dunk contest champion, was holding the ball. Munir took it out of his hands, put it between his legs and finished. He is 5'10". Griffin is 6'9". Doing that to a sitting NBA champion at his own brand event is the kind of moment that gets replayed for years.
At 5'10" with a 50 inch vertical he sits in the small group of dunkers whose jump has been measured at fifty or above, and he had that number in an era before structured jump programs were widely available. He was also named to the AND1 Summer Remix roster in 2013, alongside the touring dunkers of that generation.
Dunkademics filmed him early, and his footage from that period is part of why the current generation exists. Several dunkers on this site, including Anthony Height, describe growing up watching Young Hollywood clips on Billy Doran's early uploads and deciding to try it themselves.