There are many different types of zombies in Burn Zombie Burn. As the stages progress, more of the different types of zombies start to come in. When they are first introduced, they will come in a large wave. After all of the zombies are killed, the type of zombie that was just introduced will start to come regularly. This process continues until you get to the last type of zombie, the Super Zombie. After the last one is introduced, all types will come regularly until you lose all of your lives.
Normal zombies are the first to appear in the game, and the simplest. They have no strategies for defeating you other than surrounding you and taking you down that way. All you have to do to kill them is shoot them once, whether it be with a Pistol or a Shot Gun. It's best to hold for rapid-fire when facing these zombies, or when surrounded/being chased by a mob of them, use a Shot Gun to take down a lot at a time.