Death Metal spawns near the middle and has 9 health and 4 phases. Upon entrance, it says "Ah, welcome!"
Phase 1 (9-7 HP): Death Metal has a shield and can move every third beat, pursuing the player. It can only be hit from the side or back during this phase. When hit from the front, Death Metal takes no damage and spawns 2-3 Bats. Using a phasing weapon will hit through the shield. It is recommended to kill the enemies around Death Metal during this phase first, as Death Metal does nothing but slowly chase the player around.
Phase 2 (6-5 HP): Death Metal will occasionally shout "Come to me!" and raise its arm up. If Death Metal is not hit 4 beats afterwards, 2-3 Skeletons will spawn (Shielded in Zone 2; Mounted in Zone 3; Lich in Zone 4). Death Metal teleports away on hit.
Phase 3 (4-3 HP): Similar to phase 2, but Death Metal shouts "End of the line!", and instead spawns Yellow Skeletons (Shielded in Zone 2; Mounted in Zone 3; Lich in Zone 4).
Phase 4 (2-1 HP): Death Metal hugs the left or right wall, shouts "Breathing fire!" or "Bathe in fire!" and shoots a fireball horizontally, dealing 3 damage. Death Metal will also attack above and below itself, so it is recommended to attack horizontally. In this stage, Death Metal moves every beat, except when it is casting the fireball spell.
In the Zone 1 variant, Death Metal spawns along with four Ghosts.
In the Zone 2 variant, Death Metal spawns along with four Clones.
In the Zone 3 variant, Death Metal spawns along with two Fire and two Ice Beetles.
In the Zone 4 variant, Death Metal spawns along with two Warlocks and two Neon Warlocks.