You must hit 3 enemy Raskulls with the flame charge power-up. Power-ups can be found in presents, and are completely random. There are multiple versions of the Flame Charge to be attained in presents. There is a single Flame charge power-up and a triple Flame charge power-up. Both do the same things. Once you get one, use it with to charge through 3 enemies. The achievement will unlock after you’ve done so.
This is easily boosted if you can't get it either in single player or while playing online. Once you get a flame charge power-up, just get the other three raskulls in a line right next to each other, and use it while facing them.