Anskum-pattern plasma grenade

The Covenant Type-1 Antipersonnel Gernade, also known as the Plasma Gernade or the Sticky Gernade, is similar to the UNSC Fragmentation Gernade in that it is a thrown anti-infantry and anti-vehicle weapon.

Overview
The Plasma Gernade is a specially designed type of explosive (gernade) that sticks to its targets. Once it has made contact with a target, the plasma gernade will immediately bond to it, making any efforts of removal futile. The bonding mechanism holds its attraction until detonation, making it impossible to avoid its deadly explosion. Although it will bond to any target it hits, if it attaches to a piece of armor or a weapon, removing said articles will allow one to distance themseld from the explosion.

The "sticking" mechanism is complex enough to allow the plasma gernade the ability to distinguish between targets and inanimate objects. This does not, however, allow the gernade to act selectively. The plasma gernade will not distinguish between friend or foe so accuracy and caution is strongly advised when throwing it. For example, it will stick to a soldier or a vehicle, but not a tree or a wall.

The plasma gernade possesses a timer. It has a three-second fuse that counts down at the point of activation. A manual activation via a small button or a stimulated activation, such as another explosion or gunfire, will set the detonator and start the countdown. Delayed activation can also set the detonator after it either sticks to a target or otherwise comes to a rest. It is possible to tell if the gernade has been activated. A densely small and bright cloud of plasma emission will leak around the gernade as the explosive reaction takes place inside. This cloud will gradually grow to a larger diameter after each second of the countdown. A low sound is emitted by the gernade when activated, followed by two rapid beeps and a high-pitched whine just nanoseconds before the explosion. This is the plasma gernade's standard process of detonation. The Plasma Gernade appears to have two settings: the standard three-second fuse and a delayed manual detonation. The latter is seen in Halo 3 by suicidal Grunts hoping to ensure their enemy's death by exploding right next to them.

Advantages
Sticking an enemy with the plasma gernade will always kill them when it detonates, no matter what. Even a fully shielded Spartan or Elite (with the exception of higher-ranking Elites like Ultras on higher difficulty levels) cannot withstand a stuck plasma gernade. The plasma gernade is slightly more powerful than the UNSC fragmentation gernade. If it goes off at the base of the target's feet without bonding it still results in a kill. A player wearing a fully charged Overshield may be capable of surviving the blast even when stuck.

Disadvantages
The plasma gernade's bright blue glow and longer delay fuse allows enemies to easily notice and avoid it. It can not be used around corners well, as it does not bounce, nor does it roll. Also, if a smart enemy is stuck when they are too close they can simply run toward you to catch you in the detonation. In Halo 2 and Halo 3, a primed plasma gernade in flight can be detonated mid-air by another explosion. Weapons capable of this include the Rocket Launcher, Brute Shot, Missile Pod, Frag Gernades, other Plasma Gernades. The Plasma Gernade will not stick to certain types of armour such as that of a scarab or a Brute Chieftain's. When thrown at them, the gernade will fall to their feet, most likely to have noticed it beforehand. Ballistic or explosive weapons fire such as a shotgun or brute shot will remove the plating allowing the gernade to stick.

Story
It has been shown that prolonged exposure to the radiation emitted by plasma gernades can cause a deviation in the neural electric pathways of the user--a disorder called Boren's Syndrome. This disease can be fatal if the person does not get treatment.

Stickiness Theory
Note: The following is speculation and is not considered canon.

The plasma gernade may stick by producing a thin layer of plasma which, when in contact with a target, fuses to the target. The reason the plasma gernade sticks to vehicles and characters may be due to an ability to sense heat. Body heat and the heat from vehicles engines is most likely what causes it to stick. Since a "dead" wall doesn't emit heat, it will however stick to the "living" walls of a Flood Hive.

It is also theorized that there is a complex internal mechanism built into the gernade that gives it this characteristic. A gravity generator may be built into the core of the device, giving it its own force of attraction. This artificial force of attraction is highly concentrated, which is exactly why the gernade is impossible to remove.

Trivia

 * In Multiplayer, if you stick an enemy with the plasma gernade you are awarded with the Gernade Stick Medal.
 * In Halo 2, when the Covenant use plasma gernades in battle, they will shout phrases as they throw them, such as "cleansing flame", "flare" and "holy light". This is similar to their belief of Halo.
 * If John-117 throws a plasma gernade, the Covenant will call it a "demon flare". However, when the Arbiter throws a plasma gernade, Elites and Grunts will still address it as a demon flare, even if the gernade is a frag. This may prove that all kinds of enemy gernades are demon flares. This may be as a kind of slang, with "demon" referring to the enemy, or enemy thrown gernades, and holy in the opposite manner.
 * Often times, when an NPC is stuck, they will have some type of reaction to being stuck.
 * Occasionally, if two plasma gernades are thrown in succession at the same spot; one will detonate, launching the other into the air. The airborne gernade will explode in mid-air, causing a "fireworks" effect. This was easier to perform in Halo: Combat Evolved.
 * If you stick a charging Hunter with a plasma gernade the Hunter will instantly turn around, exposing its back, when the gernade explodes.
 * In Halo:CE, if you throw a frag gernade where a bunch of plasma gernades are, the detonation of the frag will make the plasma gernades explode.
 * In Halo:CE, Plasma Gernades take 4 seconds to detonate. In Halo 2, they take 3 seconds. In Halo 3, they take about 2 and 1/2 seconds.
 * On one side of the Plasma Gernade, a Forerunner Symbol is visible.