Christian wrote up a World of Darkness zombie inspired by AMC’s The Walking Dead (see Loviator #5). This is a B/X version. The basic idea is to make zombies more terrifying by using something like the save-or-die mechanic. In D&D, zombies are often just perceived as (slow) moving bags of HP and XP. They are only scary to the degree that they can overwhelm with numbers, and overwhelming with numbers is not very practical in D&D. Anyone who has tried to run a hoard of 40 or more monsters in D&D without some sort of simplification or handwaving should know this. This zombie is scary because it is a carrier. One bite, and you could be infected. This taps into a deep fear of contagion.
Walking dead are meant more as obstacles to avoid than as combattants to take out (though of course they can be taken out). As such, consider rewarding 0 XP for defeating walking dead in combat. Perhaps all monsters with powers such as deadly poison or level drain should actually award no combat XP? This is probably not necessary for players steeped in the old ways, but might be helpful for players coming from more recent games.
Walking Dead – HD 1, AC 9, damage 1d6 + infection, move 60′ (20′), morale 12, # 3-36
The walking dead are zombies that carry an undead plague of unknown origin. If hit by one of the walking dead, save vs. poison or be bitten. Characters bitten will become one of them in 2d6 hours. If one of the walking dead is reduced to 0 HP, it becomes immobile, but is still dangerous to anyone that comes within its reach (its reach will vary based on physical integrity). A head shot is required for actual destruction. Referees are encouraged to allow creative methods for head shots during combat.