The Greatest is an Uncommon Fortnite Spray. This cosmetic has been leaked, and the spray will hopefully be available to purchase in the near future! The Greatest was first added to the game in Fortnite Chapter 3 Season 1.
How-to Get the The Greatest Spray
The Greatest was leaked or datamined, which means we don't know for sure how it will be released. Most cosmetics that are leaked will be released within 30 - 60 days of their discovery.