Ivy (RE2 remake)/gameplay

Attack Pattern
The Ivy Zombie will attempt to close and grapple with the player character, just like a normal zombie. However, unless foiled with the use of a Defensive Weapon, the Ivy Zombie will decapitate the player character by biting off their head, resulting in an instant death.

Strategy
An Ivy Zombie can be temporarily rendered quiescent by precisely shooting the pulsating yellow bulbs that adorn its body. How many bulbs are present and where they are located on its body varies between individual Ivy Zombies. If taken down in this manner, the Ivy Zombie will eventually regenerate and come back to life. It cannot be killed permanently in this manner.

The Flamethrower inflicts considerable damage to an Ivy Zombie. Once set alight, it will be "stun-locked"; unable to attack as the flames consume it. This will rapidly cause it to collapse in its comatose state, as per shooting the bulbs. If the body is subjected to more fire whilst lying dormant, it will eventually catch fire and burn into a blackened husk; this is a complete death for the Ivy Zombie, and it cannot regenerate from this state.

A single Flame Grenade from the Grenade Launcher will immediately burn an Ivy Zombie into its dormant state. A second Flame Grenade in this state will kill it permanently.

Arguably the most ammo-efficient way to dispatch an Ivy Zombie is to disable it with precise handgun shots to its bulbs, and then burn it with the Flamethrower or Flame Grenades whilst it is in its dormant state.