The All Terrain MegaCaliber Six (AT-M6), also known as the Gorilla Walker, First Order Heavy Assault Walker or First Order AT-AT, was a mobile heavy artillery walker used by the First Order during their war with the Resistance. Much larger than the All Terrain Armored Transport used by the Galactic Empire, it was the biggest walker in the First Order's arsenal and featured a megacaliber six cannon mounted to its back, for which it was named.