If a player has this item in possession, they can select SD: Zombie Scenario sub-mode. The gameplay is similar to Zombie Scenario except that the head of every characters in the game will inflate, making the head expanded. It is easy to perform headshot as the size of the head has increased. The storyline remains unchanged. This item is available for 2 weeks after the release.
- South Korea: 16 May 2012.
- Japan: 30 May 2012.
- Indonesia: 2 January 2013.
- CSN:Z: 27 November 2014.
- Vietnam: 9 April 2015.
- "Soy" refers to Senior Researcher Soy.
- "SD" means "Super Deformed".
- Some models' hitboxes might not be affected, so projectiles do not land in their heads.