Bayonet

A bayonet (from French baïonnette) is a bladed melee weapon such as a knife or short sword, or spike-shaped weapon designed to fit in, on, over or underneath the muzzle of a rifle, musket or similar weapon, turning it into a makeshift spear. Knife-shaped bayonets—when not fixed to a gun barrel—have long been utilized by soldiers in the field as general purpose cutting implements. In contemporary combat it is mostly used as a last-resort weapon if one runs out of ammunition or there firearm jams or breaks.

Bayonets can be effective in combat for this psychological reason: Having a bunch of guys running at you with improvised spears and screaming for blood can be scary! Especially if it is unexpected like the 2004 British bayonet charge in Iraq.

On the wiki
Ethan Allen Fernandez usually has a bayonet fixed to his weapon, "Black Betty", in Weapon Wielders. The bayonet is a weapon attachment in Call of Duty: Underground, and Call of Duty: Axis Powers. The M9 bayonet is a weapon listed as being used by the Joint Operation Forces in the Call of Duty: Future Warfare series. The bayonet is also a weapon in Red Dead Revolver 3dn edition, and Red Dead Redemption.