ZED Evolution - From KFMod to Killing Floor 2

The ZED roster has been around since 2005, when Killing Floor was a total-conversion mod for Unreal Tournament 2004. Every version since kept the same core lineup and naming, but redrew, re-voiced and rebalanced it. Comparison videos that put each specimen side by side on maximum settings are the easiest way to see that lineage, and this page walks through it specimen by specimen: what changed, what stayed, which ZEDs never shipped, and how the seasonal events reinterpreted the whole roster.

Knullworks: every franchise ZED in one 45-minute compilation.

The eras at a glance

Era	Year	Engine	What it means for the ZEDs
KFMod 1.0	2005	UT2004 mod	The first, rough roster. Low-poly models and simple animation, but the core archetypes already exist.
KFMod 2.0	mid-2000s	UT2004 mod	New models; the Crawler and Siren appear.
KFMod 2.5	mid-2000s	UT2004 mod	Refined models and behavior; the mod closes in on what retail would become.
Killing Floor	2009	Unreal Engine 2.5	Polished models, the full classic roster including the Husk, seasonal event sets.
Killing Floor 2	2015-2016	Unreal Engine 3	Full redesigns, M.E.A.T. gore, new specimens and five bosses.
Killing Floor 3	2025	Unreal Engine 5	Augmented classics plus Mire-born creatures.

Background on the mod years: history of the creation of Killing Floor, development history and the prototype.

Inside the mod: 1.0, 2.0 and 2.5

The Clot in KFMod 1.0, 2.0 and 2.5, left to right.

The mod changed visibly between releases. KFMod 1.0 ZEDs look like early prototypes: dark, low-detail skins and stiff poses. Version 2.0 switches to pale, almost clinical skins. Version 2.5 adds dirtier, yellowed textures that already point toward the retail look.

Roster by mod version, based on the Knullworks comparison:

Specimen	1.0	2.0	2.5
Clot	Yes	Yes	Yes
Bloat	Yes	Yes	Yes
Gorefast	Yes	Yes	Yes
Crawler	No	Yes	Yes
Stalker	Yes (female Clot model)	Yes	Yes
Siren	No	Yes	Yes
Scrake	Yes	Yes	Yes
Fleshpound	Yes	Yes	Yes

In KFMod 1.0 the Stalker reused a female Clot model.

The Fleshpound grows from a lanky mutant into the armored brute players know.

KFMod 1.0 in motion

BeavisOfArabia's video plays through KFMod 1.0 and introduces its specimens in the rain-soaked opening map. Some names from that era, such as the Wretch, never made it into the retail game.

KFMod 1.0 introduces a specimen called the Wretch.

The Scrake's first appearance in KFMod 1.0.

Unused models

The compilation also shows models that were made but never used:

• Shade (KFMod 1.0): a dark, shadowy specimen.
• Ranged Fleshpound (KFMod 2.5): a Fleshpound variant meant to attack from a distance.

The unused Shade from KFMod 1.0.

The unused ranged Fleshpound from KFMod 2.5.

More leftovers are collected in cut content and unused models.

Playing the mod today

All three versions are archived on ModDB, and each needs Unreal Tournament 2004 installed. The 2.5 release (also available as a 2.52 zip) is the most complete.

The classic lineup, era to era

The comparison videos always follow the same order. Here is what changes for each specimen.

Clot

Clot: KFMod, KF1 and KF2.

The basic grabber barely changes its role. Each generation makes the silhouette cleaner and the animation heavier. KF2 adds the Alpha Clot and the armored Rioter as tougher variants of the same idea.

Bloat

Bloat: KFMod, KF1 and KF2.

From a stretched, yellowed body in the mod to the pale, swollen KF1 model and a fully grotesque one in KF2. The bile attack stays the same throughout.

Gorefast

Gorefast: KFMod, KF1 and KF2.

The blade-armed sprinter gets redder and more muscular each time. KF2 adds the Gorefiend, a two-bladed upgrade.

Crawler

Crawler: KFMod, KF1 and KF2.

Absent in KFMod 1.0. From 2.0 on it is the spider-like jumper that every version keeps. KF2's Crawler is the most insect-like.

Stalker

Stalker: KFMod, KF1 and KF2.

The cloaked flanker keeps her invisibility in every version; only the model and the cloak effect change. In KF2 the Commando perk reveals her.

Siren

Siren: KFMod, KF1 and KF2.

Introduced in KFMod 2.0 as a straitjacketed woman whose scream damages and destroys projectiles. The design stays close across all versions.

Husk

The KF1 Husk, the clearest addition of the retail era.

The KF2 Husk keeps the arm cannon and adds a flamethrower and a suicide attack.

The Husk has no mod-era version in the comparison. It arrives with retail Killing Floor and gives the roster its first real ranged threat.

Scrake

The mod-era Scrake next to its retail successors.

The chainsaw-wielding butcher keeps its role as the ZED you should not anger with weak weapons. KF2 gives it a heavier, more armored look.

Fleshpound

The KF2 Fleshpound.

The rage tell, a light on its chest that changes when it is about to charge, carries across every version. KF2 adds the smaller Quarter Pound and the King Fleshpound boss.

Patriarch

The KF2 Patriarch.

His kit (minigun, rockets, cloak, healing) stays the same from the mod to KF2, where he gets a fully staged fight. See the KF1 Patriarch guide and KF2 bosses.

Knullworks: KFMod vs KF1 vs KF2, updated to 4K and Ultra settings.

Voice lines are part of each ZED's identity too. Every generation re-records them, and comparing the same specimen across eras is as much about hearing the change as seeing it.

New specimens in Killing Floor 2

The Rioter, an armored Alpha Clot variant.

The Blaster E.D.A.R., one of KF2's robotic enemies.

Specimen	Based on	What it adds
Alpha Clot	Clot	Tougher, can rally nearby ZEDs
Rioter	Alpha Clot	Heavy armor, needs focused fire
Gorefiend	Gorefast	Two blades, more health
Quarter Pound	Fleshpound	Smaller, faster, rages too
E.D.A.R. (Trapper, Blaster, Bomber)	Horzine robots	Mechanical enemies with ranged attacks
Bosses	-	Hans Volter, Patriarch, Matriarch, King Fleshpound, Abomination

Full KF2 roster: KF2 ZED types.

Seasonal ZEDs

Both games run seasonal events that reskin the whole roster for a few weeks. The compilation lists every set:

Game	Seasonal sets
Killing Floor	Summer Sideshow (circus), Hillbilly, Halloween, Christmas
Killing Floor 2	Summer Sideshow (circus), Halloween, Christmas

KF1 Summer Sideshow: the Husk as a clockwork circus machine.

KF2 Summer Sideshow: the Matriarch in a diving-suit carnival look.

KF2 Halloween: the Abomination Spawn.

Christmas: KF1 against KF2

The Christmas sets show how the same idea was reinterpreted a generation later. KF1's "Twisted Christmas" uses elves, Santas and toys; KF2 pushes the designs further and gives several of them new themes.

Christmas Clot: KF1 elf (left), KF2 elf (right).

Christmas Gorefast: both games turn it into a gingerbread man with a candy-cane blade.

Christmas Stalker: a festive costume in KF1, an ice creature in KF2.

KF1 Christmas: the Husk becomes a snowman.

Christmas Patriarch in KF1 (left) and KF2 (right).

Specimen	KF1 Christmas	KF2 Christmas
Clot	Elf	Elf
Bloat	Santa	Krampus-like figure
Gorefast	Gingerbread man	Gingerbread man
Crawler	Antlered spider	Candy creature
Stalker	Festive costume	Ice creature
Husk	Snowman	Snowman-themed, top hat
Scrake	Silver spiked suit	Reindeer
Fleshpound	Nutcracker	Nutcracker
Patriarch	Santa	Santa

Knullworks: Christmas ZEDs in KF1 vs KF2.

Event details: event content and launching event ZEDs on your own server.

And Killing Floor 3

KF3 continues the lineage with augmented versions of the classics and Mire-born newcomers such as the Scavenger and the Chimera. See the Mire lore and the KF3 hands-on preview.

Sources

• Knullworks, ALL Killing Floor Franchise Zeds in 4K/ULTRA SETTINGS, August 2024.
• Knullworks, Killing Floor Zed Comparison/Evolution (KFMOD/KF1/KF2) Updated to 4K/ULTRA, December 2023.
• Knullworks, Killing Floor MOD Zed Comparison/Evolution (KFMOD 1.0 / 2.0 / 2.5), December 2023.
• Knullworks, Killing Floor XMAS Zed Comparison/Evolution (KF1/KF2), December 2023.
• BeavisOfArabia (TCR), KFMod - The Zeds of KFMod 1.0, May 2021.

Screenshots on this page are frames from these videos.