Zero Knuckle

The Zero Knuckle (ゼロナックル) is a weapon used exclusively by Zero in Mega Man Zero 4, replacing both the Shield Boomerang and the rod weapons used in previous games. The Zero Knuckle consists of a Z-shaped chip implanted into Zero's palms. By punching enemies with the chip, Zero can rip off enemy parts and use them. A successful theft of such a part normally results in the destruction of most enemies, but some enemies like Yadokroid and Lamplort X will lose a part first. The weapons or parts can have a number of uses, and some have limited ammunition. If a stolen weapon is out of ammo or simply of no use any longer, it can be thrown away by pressing Select or in the pause menu, which can hurt an enemy as well. Since Elemental Chips have been omitted from the game, it's unknown if the Zero Knuckle can use the chips like Zero's other weapons. It can also be charged, however the charged version of the Zero Knuckle is only a stronger punch. It is unknown whether this weapon was created by Cerveau or had been part of Zero all along, but artworks of Omega from Mega Man ZX show him having a Knuckle on his own, but with an Omega symbol (Ω) instead of a Z; this is most likely used for the Rekkoha and Rakuhouha.

The Weapon Plus Head Chip can increases max ammo by 1.

List of Zero Knuckle weapons
Zero can hold only one of these weapons at a time.