According to Make-A-Wish, Blizzard has donated $1,000,000 to the charitable organization. The money comes from the November and December 2013 sale of the Alterac Brew Pup; which given that 50% of the proceeds from the sale were going to the charity, means that the in-game pet brought in $2 Million for Blizzard.
Blizzard has a long history of working with Make-A-Wish. Besides donating over $3 Million since 2010, they also have done amazing things like bringing in the late Ezra Chatterton to get his own weapon, receive a character boost before anyone else, get the first Ashes of A'lar in the world, and generally have an awesome day.
We firmly support Make-A-Wish and the life-changing impact of a wish experience," said Mike Morhaime, according to Make-A-Wish. "We're also incredibly grateful for the generosity of our World of Warcraft players- we're always proud to work with our community in championing a good cause."