Final boss

The Icon of Sin is the boss of Doom II MAP30: Icon of Sin as well as MAP30 of TNT: Evilution and Plutonia. See the walkthrough for a gameplay description.

All the other monsters are a single Doom thing, but the Icon of Sin is made up of a number of parts:
 * Romero's head is the thing that must be destroyed. It starts with 250 hit points.
 * A Spawn shooter in front of the head launches skull cubes.
 * Several Spawn spots are located around the map; they are the targets for the shooter.
 * Wall textures ZZZFACE1 through ZZZFACE9 are arranged to construct the demon face with a hole into the brain.