Dead Ahead: Zombie Warfare

"Undead" is a specific name for a Zombie in this game

There is a guy with a hat and a hockey stick. I can't tell if it's the Lubber or Bulletproof Zombie, but when he dies, he will resurrect as an "Undead" type zombie. This is the guy you need to hit with a molotov and the achievement should pop.

I encountered this zombie first on level 33. I'm not sure if they don't resurrect, or just don't appear until here, but I think this is the earliest you can get it. Mention below if you found an earlier level to do it on.

Here's a picture of him from the in-game guide.



Here's a video of when I got the achievement. The method might be slightly different based on your troops strengths, but basically earn 15 rage points, Kill the guy in the hat, then hit him with a molotov.