Gearbox Software has announced that Alani, the first of five free DLC characters for Battleborn, will be available for everyone on May 31st, but will cost 47,500 in game credits so get earning. That is unless you have the Season Pass, purchased the Digital Deluxe version, or participated in the PS4 open beta for Battleborn. If you fall into that category then you can get Alani from May 24th.
Players who do fall in that group will receive a Hero Key which unlocks any hero in Battleborn. Additionally these Hero Keys are reusable and are returned once you reach the command rank for the unlocked character, or if you complete the challenge objectives. This weekend will also be the start of Double XP in Battleborn too, commencing on May 20th and finishing on May 25th.
The character Alani is part of the Eldrid faction, raised as healer but made to be a fighter too. Her abilities revolve around the use of water, which can inflict damage or be used to heal fellow team mates.
Source: Battleborn Site