The Created Undead in RMC CM get into that a bit. . .RM undead regenerate.
So, unless you de-fleshed the zombie to make it skeletal, then destroyed the flesh permanently or locked it up in a box, it'd just re-build back to rotting corpse look.
The early types just come back together, so will look like a mass of rotting burger. . .as they advance type, the flesh re-builds progressively better, until the max type look like perfect, if pale people with rings under their insane eyes. . .along the way you get progressive versions. . .like the "flesh re-builds but skin doesn't" tattered looking types that'll eventually if they keep going and taking damage, end up skinless zombie types.