The Pioneer is the Kingdom Karnage Founders Token (FT), it is an epic character in game, and a great way to get extra character cards.
Each month a new quest is available to anyone who has a Pioneer. Complete the quest any time during that month, and you will receive the relevant reward on the 1st of the next month. To see the latest Pioneer challenges and your progress please view the events page
There are only 1000 Pioneer FTs and all are in circulation. The Pioneer can now only be purchased from other players, you can find him in the in-game auction house.