What Is a Blaze and What Do They Do in Minecraft. Blaze are floating mobs only found in the nether. They're essential because they are the only source for Blaze Rods. The second a Blaze sees you, it'll begin attacking you and will shoot three fireballs towards you.

blaze verb (BURN)\n\n to burn brightly and strongly: The fires blazed for days. If someone's eyes blaze, they seem to shine brightly: Her eyes blazed with anger.