Homebrew
darkvision 60ft, passive perception 8
Undead Fortitude.
If damage reduces the zombie to 0 hit points, it makes a Constitution saving throw (DC 5 + the damage taken), unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.
Clumsy Shambler.
The tiny zombie has disadvantage on Dexterity saving throws and cannot take reactions.
Rotting Nuisance.
When the tiny zombie ends its turn within 5 feet of a creature, that creature must succeed on a DC 10 Constitution saving throw or have disadvantage on its next attack roll (a faint, sickening stench and distracting twitching).
Bite.
Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 3 (1d4+1) piercing damage.
Claw.
Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 2 (1d3+1) slashing damage.