The King Roo events are where players have a chance to earn a share of all slot wagers across a number of days if they become King Roo. In order to become King Roo you need to hit a 100x+ multiplier on any slot during the event, you will then be King Roo until a different player hits a 100x+ multiplier.
King Roo gets a % of all slot wagers across the entire site from every player for the duration they are King Roo, this % is paid out in real time as the wagers are made. You can check your payouts and see your winnings incoming to your account in your transaction history. These King Roo payments are called ‘koth’ in your transactions. Here is a screenshot of what they will look like in your transaction history:
As you can see above, these payouts are extremely frequent and are a % of each slot's wagers, these are typically paid out multiple times per second and can add up to very large amounts depending on how long you are King Roo.
The longer you are King Roo, the more you will earn, the highest earners from King Roo will be visible on the leaderboard on the slots page, which looks like this:
There are no rewards for leaderboard placements, as by the time a user is on the leaderboard they will have already earned a substantial amount from the time they have been King Roo!