Watch the latest trailer for Halo Infinite to see what to expect with The Yappening II, which features new Grunt-themed rewards, Gruntpocalypse, and more. The Gruntpocalypse features two weeks of all-out PVE Grunty goodness. Week three brings Corrosion to the game. Set in an abandoned mineral refinery on Zeta Halo, Corrosion is a new Arena map created in Halo Infinite’s Forge that poses peril with its acid pits.