Here are the patch notes for today's update to Heroes of the Storm, Blizzard's MOBA. The update adds new early game character scaling changes and kicks off Cho'gall Hero Week, introducing the game's new two-headed hero. For the time being you cannot buy the new hero, who was handed out to BlizzCon attendees as well as some random players. Here's word on how he's being spread virally:

• Cho’gall Awarded to BlizzCon Attendees
  • All players who attended BlizzCon 2015, or purchased a Virtual Ticket, will permanently receive Cho’gall in their Hero Collections.
• Unlock Cho’gall by Playing with Friends
  • Cho’gall cannot be purchased using Gold or real money.
  • Instead, players who don’t own the two-headed ogre can unlock him by completing a brand new Special Event Quest!
• Special Event Quest: Cho’gall Buddy Brawl
  • Win 2 Games as Cho or Gall while partied with a player who owns Cho’gall to permanently unlock the Hero.
  • Win 4 games as Cho or Gall while partied with players who have not yet unlocked the hero to earn 2,200 Gold.
    • Those who own Cho’gall may only earn this gold reward once. However, they can still help as many other players unlock the hero as they wish.