Plants vs. Zombies: Battle for Neighborville

At the moment the easiest way to do this to go to giddy park, head to the globe just before the pvp area and switch to private with A.I then jump into the pvp zone going to the opposite end near the opposing sides' spawn and just kill the wild flowers or tv head zombies these vanquishers count as kills towards this achievement.

Pretty easy achievement. This can be earnt quickly by simply camping at the opposing team's side in Giddy Park and grinding the bots that appear there. Just keep on vanquishing them for about 10 minutes and the achievement should unlock.