Several Doom 3monsters, characters, and art designs were cut in the development process and did not make it into the finished game. Id Software first experimented with sculpting and scanning VS modeling but the data was dense and unwieldy, so they abandoned it pretty quickly. Various concept designs of these monsters were shown amongst the pre-release Doom 3 promo material. One of them was a new version of the Arachnotron and Spider Mastermind (seemingly cut in favor of the other new arachnoid monsters Trite and Vagary) while the rest were apparently new designs. Eventually some of the unfinished monsters were finished and used in the Doom 3 expansion, Resurrection of Evil.
An Arachnotron concept drawing that was cut from the game.
Spider Mastermind Concept drawing.
An early Imp sculpture.
An early Hell Knight sculpture.
An unused monster (aka Birdman).
Concept art of a unused demon.
Concept art of a unused demon with different heads.
Early zombified Marine or Security model (Holding an unused rocket launcher).
Early Human Sarge & Zombie Sarge revealed at macworld 2001.
Early UAC Marine model. This model is used in the ios handheld game Doom Resurrection.
Early Marine or UAC Security.
A concept art drawing of the Marine.
Another concept art drawing of the Marine.
High-resolution model renderings of Zombie's heads with damage.
A mutated zombie concept.
A fat mutated zombie or demon concept.
Concept drawing of a Mancubus.
A concept of an unused demon (possibly a Guardian, Hell Knight, Baron of Hell)
Concept drawing of an unused character.
Concept drawing of an unused enemy.
A model of an unused version of the Helltime Hunter from Doom 3 Resurrection of Evil, a unused texture is located within the it's folder
Early Chainsaw Zombie.
An alternate skinned Trite.
Early Archvile. Later became the Vulgar in Doom 3: Resurrection of Evil.
Possible early designs of the Bruiser from Resurrection Of Evil.