The MP5A4 is a non-canon, full-automatic SMG featured in some fanon maps.
Remember When...[]
The MP5A4 appears in the Remember When... storyline. It has a moderately fast rate of fire, recoil and penetration power. It is one out of eight submachine guns in the storyline. It has moderate damage which makes it extremely useful in early rounds, despite being one of the weakest submachine guns. This weapon has a large ammo conserve of 300 rounds in reserve and 30 already in the weapon. It can only be obtained from buying off of the wall.
Effectiveness[]
The MP5A4 is a good weapon to keep with you in early rounds, despite being one of the weaker submachine guns. It has a one-hit kill ability up until Round 3. Its moderate recoil and automatic firing mode can make it difficult to accurately hit zombies while blasting. To compinsate for this, burst-firing is recommended as it increases the weapon's accuracy and conserves ammunition. Its moderate penetration power makes it useful for shooting through thin objects like wood and sheet metal, but it is not recommended. This weapon should be pack-a-punched by Round 12.
Pack-a-Punched Variant[]
When pack-a-punched, the MP5A4 becomes the Tree Killer. After it is upgraded, it's damage increases to 280-355 and its magazine size increases to 45 rounds. Its reserve ammo increases to 450 rounds as well. This weapon gains a red dot sight after it is upgraded. It is recommended to trade the Tree Killer for a better weapon by Round 18.
Casted Shadows[]

The MP5A4 is scheduled to appear in the Casted Shadows storyline.