Junkenstein's Revengance!
There's a new 12-wave into endless survival mode with wider hero choice, new enemy hero (Symmetra as the Summoner - plops a Shield Generator at the start of her phase and goes for the microwave gun), and new skins, including the Summoner (well, Dragon), a new Reaper skin (Dracula), Van Helsing for McCree, and a Cthulhu-esque skin for Android Krillin, among others.