Zombie Modifiers are special properties zombies can have. They can be very dangerous, like Extra Strong and Fiery Skin, or just plain annoying, like Regenerating or Chintinous Hide. Here are the list on modifiers in SAS4 (or 5).
Teleports towards you. Can teleport up to 25 meters. For comparison, a Gebirgskanone has a blast radius of 0.8 meters.
Appearance: Flashes purple randomly.
United Zombies stick together. This could be good or bad. When at least 3 united zombies are together, attack is boosted by 5% per zombie
Appearance: Glows yellow.
Parasited Zombies always have at least two Worms or Puke Worms with them. Any zombie who already have or spawn worms (i.e. Bloaters and Regurgitators) will double the amount of worms spawned. Any "upgraded" zombie will spawn "upgraded" worms. (i.e. If an Apex Shambler is parasited, then it will spawn at least two Apex Puke Worms or two Apex Worms). The limit is six.
Appearance: Has the kind of the worm and the quantity which has in the zombie's back, trying to enter in the body.
Blocking zombies have 50% resist to all attacks. It also has an aura around it, which blocks attacks for other zombies. Hence the name.
Appearance: Red aura around them. Also are slightly tinted green.
This modifier gives zombies a double damage, 10% more speed, and releases 2 Filled of a lower teir. e.g a Filled apex stalker turns into 2 Filled evolved stalkers which each turn into 2 Filled fetid stalkers each turning into 2 Filled stalkers who turn into 2 normal stalkers.
Appearance: Twice as large and has clear skin, showing 2 zombies floating around in its stomach.
Zombies like this fly over walls, do 2x damage, but have 20% less speed.
Appearance: Has wings and is black.
Two zombies are already stick together, thus, abilities from the zombies are combined. This kind of zombie can attack forward and backward at the same time. Both siamese twins can be Fetid, Apex or Evolved. They can share the same modifiers. Once one zombie is dead, the dead corpse will de-glue from the other zombie, and thus, making him free, acting by himself. Bosses can have this modifier.
Appearance: Two zombies sticked together.
Trogdor Infernal Rage
Zombies with this modifier are capable of throwing smaller versions of the Wicker's fireballs
which burninate everything in their way, in addition to having an immunity to thermal damage and a 10% resistance to energy damage.
Appearance: Flame aura around zombie; smoke trail behind it for 3 metres.
Extra Resistant zombies have 10%, 15%, 25%, 40% global resistance but resistance-piercing attacks and AoE attacks ignore all this resistance.
Appearance: Has a metal-looking outline around it.
Intensely Mutated zombies have all SAS4 modifiers and modifiers made by LeotheFox at once! However, Intensely Mutated zombies have 2x larger hitbox. This modifier can only appear if an Apex zombie with already 3 present modifiers on it is lucky enough to get to the 1% chance of spawning with this modifier. Intensely Mutated zombies will give 5x as much EXP as they normally would.
Appearance: Is 2x as big, has 100% saturation, and has some tentacles coming out of their back. They also make a Devastator sound when spawning.
Only Spitters can get this modifier. Jet Spitting Spitters, instead of spitting just a small amount of acid, will spit a solid beam of acid that has 15m range. It also bounces of walls. Jet spits will leave a long pool of acid that has the same hitbox as the jet spit.
Appearance: Has a small Acid Blood effect coming out of its mouth, is slighty more yellow-coloured.
Upon the death of an enemy carrying this, it will spawn the zombie from the next tier down, it will also have this modifier (e.g a fetid Stalker with Bloon Genes? on death will drop a regular Stalker that has Bloon Genes?). The opposition will only be beaten once you bring it down to a regular variation and kill it, leaving it nothing to reduce to.
Appearence: It will have a rubber-y shine.
Loot Carriers almost always drop loot on death. This extra loot weighs them down, reducing its movement speed by 5%. Loot Carriers however have a much greater capacity for modifiers (letting them hold up to 5! (Not including Loot Carrier itself)) as well as a greater chance to get modifiers. More powerful zombies will get better loot than weaker ones. They don't usually carry things like ammo, health and cash.
Appearence: They have whatever loot they're carrying on their back.
Things with Darkened Aura are monstrously large, so much so that they're barely mobile at all! However things with this hit VERY hard in CQC. Any projectiles the carrier fires are vastly enhanced; they get a speed, damage, AOE and effect buff of 50%!
On top of all of that, if the player gets within a radius of the carrier a black, wavy beam will connect between them both. The player will take between 1 and 5% of the damage of the carriers primary attack (the percentage will grow as the victim gets closer to the carrier). This beam can be broken by either getting far enough away from the carrier or by killing it.
Appearence: A black "cloud" surrounds the carrier
Zombies with this have 75% Electric resistance and do 50% shock damage.
Appearance: Similar to Energy Resilient, but 10% larger, more common "shocks" and nearly transparent bluish aura.
Zombies that are Suicide Zealots will charge towards the closest player and go boom if they aren't stopped. Only Runners and Stalkers have this modifier. It replaces Extra Fast. Suicide Zealots move as fast as if they were Extra Fast.
Appearance: Sparks will surround the zombie. They are dull orange when the zombie is idle, and they glow aggressively yellow when they see a player.