Let's Read the 4e Creature Catalog: Zombie
The Lore
Zombies in Athas have the same origin as zombies in every other D&D world: they’re created either intentionally by necromancy, or accidentally from dead bodies left for long enough in areas exposed to strong necrotic energies.
In Athas that means areas touched by the Gray, the Darker and Sunnier version of the Shadowfell. Any bodies left in these places have a high chance of rising as zombies. As the natural environment in these areas tends to be particularly harsh as well, they can do interesting things to these bodies before they rise.
The most common of those is that by the time the body rises its flesh is long gone due to the actions of predators and scouring winds, so you get a skeleton instead. But some places like the ones named below can preserve the flesh of a corpse, giving enough time to rise as a Darker and Sunnier Zombie with extra powers.
The Numbers
The zombies described in this entry are Natural Humanoids, which I think is an error because every other zombie is a Natural Animate. In any case, they have the Undead tag and the usual immunity to poison and disease and resistance to necrotic damage. They also tend to be faster than standard zombie varieties (which still exist in Athas!).
Salt Zombie
These are created from the big necrotic zone in the Salt Meres. They tend to lie beneath the salt flats, erupting out of the ground when they sense living beings walking the surface. They probably look dried out and mummified.
Salt Zombies are Level 1 Soldiers with 28 HP and a ground speed of 6. Their necrotic resistance is 5 and they have Vulnerable 5 to Radiant damage. Their basic claws damage and grab on a hit, but their Salt Feast attack is usually more effective: it does the same damage and also grabs, but the target has a -4 penalty to escape the grab and takes another 5 damage every time they fail. And of course, the zombie can also keep attacking the grabbed target either way.
They also suffer from the Zombie Weakness that afflicts a lot of standard zombies, and so are instantly destroyed when someone scores a critical hit on them.
Black Reaver Zombies
There originate from the Black Sands region. Legend has it that an ancient act of defiling magic summoned these sands into the region, and that they drained the souls of everyone they touched. There’s a creepy deserted city at its center, which was presumably the target of this magical WMD. Modern Athasians tend to give it a wide berth, and anyone who dies here will probably rise as one of these zombies.
Black Reavers are Level 5 Lurkers with 51 HP and a zippy ground speed of 7. They’re blind, and so have the corresponding tag and are immune to blinding and gaze attacks, perceiving the world through their Blindsight 10. Their necrotic resistant is 10, and while they don’t take extra damage from radiant damage it does prevent them from using their Shadow Burst power for a turn, basically defanging them for that time.
You see, their basic bite does a relatively weak mix of physical and necrotic damage, so they really need the extra necrotic damage from attacking a target that couldn’t see them at the start of their turn in order to be a threat to equivalent-level PCs. And the most likely way for them to get that bonus is Shadow Burst (recharge 4+), a move action that lets them teleport 5 squares and create a Burst 1 zone that blinds everyone inside around their arrival point. This zone lasts for a turn.
When using these in an encounter, you might want to add plenty of vision-blocking terrain to the battle map, like ruined buildings or big rocks. A zombie without Shadow Burst could still get that damage bonus if it was behind such terrain before charging out and attacking, something its high Speed would help with. Darkness also helps, but not as much since PCs are likely to have many options for lighting up the place.
Feasting Zombie
This one appears in the Forest Ridge where halflings live. Halflings who catch terminal diseases are not eaten when they die, for obvious reasons. Instead, they’re buried, which is believed to return them to nature’s embrace. This alternate funerary practice is less effective at preventing them from rising as zombies when conditions are right.
Feasting zombies are Small, since they originate from halflings, and they’re Level 6 Minion Brutes with Speed 5. They bite, and when they die they perform a Clamping Bite Death Chomp, which does the same damage as the bite attack and also slows (save ends) because the dead zombie doesn’t let go until you pry it off.
Cinder Zombies
These were killed and preserved by fire. This could be because they lived in some of the volcanic islands in the Sea of Silt, of because their village was torched by raiders. They’re charred instead of rotten, and therefore smell of burned meat. They’re also quite strong.
Cinder Zombies are Level 12 Soldiers with 121 HP and Speed 5. They have Resist Necrotic 15, Resist Fire 10, and Vulnerable Radiant 5. They project an aura of Burning Embers that deal 10 fire damage to any enemy who leaves the aura, giving them an incentive to remain close. They pummel enemies with their Fists of Cinder that do a mix of physical and fire damage. If an enemy within their aura makes an attack that doesn’t target them, the zombie uses Punishing Sparks on them to deal a bit of fire damage on a hit. When the creature is first bloodied, it releases a Choking Cloud that attacks the Fortitude of enemies in a Close Burst 3. On a hit it deals poison damage and prevents them from spending healing surges (save ends). On a miss it deals half damage and prevents surge expenditure for a turn.
Encounters and Final Impressions
While the four zombie types presented here are new, they’re still zombies. You use them in the same way you use standard zombies which, again, exist on Athas. I think I like the cinder zombies the most, as they have an interesting Defender Aura-like setup and fire zombies make sense in non-Athas settings too.
While three of the four zombies presented here are strongly associated with their specific home regions, there’s nothing preventing an enterprising villain from importing them to wherever their lair is, or from somehow replicating the process of their creation in a lab.