Æons of Death
Æons of Death is a massive compilation WAD that brings together monsters, weapons, and items from numerous games, such as Heretic, Hexen, Quake, Quake 2, Quake 3, Half-Life, Duke Nukem 3D, Blood, Shadow Warrior and others. ZDoom is required to play it.
The mod uses a randomization code which causes any monster or weapon in a certain class to spawn a random monster or weapon respectively. For example, in place of an imp, a snake imp, or a kilmaat, or a catharsi, or one of several others might appear. Also, in place of a shotgun, a shotgun from Doom 3 or the Arc of Death from Hexen might appear. This guarantees that it will never be the same game twice.
6.02 includes many new weapons and monsters.
6.06.1 introduces the ability to toggle different themes on and off based upon user preferences, along with a number of other customizable options to further enhance gameplay to how players desire it to be. This version is compatible with the later versions of unofficial ZDoom compilations, which fixes a bug causing the mod to become unplayable on 6.02 and older.
This WAD was awarded Worst Wad at the 17th Annual Cacowards. 
- Download Old Version 3.01 at iddqd.game-host.org