Big Tree is the first map that supports the Zombie Bot game mode. It promotes to basic Zombie: The Original system with the addition of bots. Bot navigation has been tweaked a bit so that it is compatible with Zombie modes. These modifications to bots are:
- New function: zombie safe area.
- No attack delay to all bots.
- If one teammate is infected in a camping area, other human bots will rush to another safe area. There are two safe areas for bots in this map.
This map was released alongside M32 MGL on:
- South Korea: 28 June 2012 with Z-VIRUS patch.
- Taiwan/Hong Kong: 4 July 2012 with Z-VIRUS patch.
- China/Japan: 4 July 2012 with Z-VIRUS patch.
- Indonesia: 10 April 2013.
This map was released alongside SKULL-1 on:
- Singapore/Malaysia: 27 March 2013.
This map was released alongside MG3 on:
- Turkey: 4 June 2013 alongside Zombie: The Original.
This map was released alongside Open Beta Test on:
- CSN:Z: 23 September 2014.
- Vietnam: 26 March 2015.
|Kill 30 zombie bots in one day period.||
Random cash weapons for 3 days or Level 2 Experience coupon.
[Bot Zombie Master]
|Gentleman, you shouldn't belittle on them just because they are dead. Don't forget they are zombies.||Unlock Difficulty Level, 'Elite', in Bot Zombie Mod.|
- In the tunnel there are rats and bats; the bats will fly out once any player enters it. Near the big tree, there are also a few rats which can't be interacted with.
- The rats model is taken from a cut model in Half-Life, while the bats model are taken from Banshee's Pulling ability.
- This map is used as a tutorial map for Zombie mode.