and yes, I am familiar with Cover of Darkness.
Like I said, I'm really just trying to come up with a good zombie that would make everyone get that fuzzy feeling inside.
Like Lackey or Piledriver does for goblins.
This doesn't seem like a good idea to me. Goblins make people feel "fuzzy" because they're good to the point where just
being a goblin is considered a bonus on a red creature. The answer to making people feel good about zombies should not lie in trying to make them as powerful as goblins.
I have to admit that tribal themes don't really appeal to me. I don't like it when a subset of cards discourages you from playing with cards outside the subset.
Generally speaking, here's how I like to see a card like this executed:
Putrefying Pathfinder
1BB
Creature -- Human Rogue
1/1
Nonzombie creatures you control have swampwalk.

, Sacrifice a zombie: Target land becomes a swamp until end of turn.