The Holy Hand Grenade is a special grenade in SAS: Zombie Assault 2, SAS: Zombie Assault 2 Insane Asylum, and SAS: Zombie Assault 3. When walked into/thrown, the whole screen turns white, killing a lot of Zombies. Its pin is a cross, which in many religions is a holy object, hence its name.
In SAS 2/Insane Asylum, they are used as soon as they are walked into. In SAS 3, the player can keep them and use them whenever they like by throwing them, much like regular grenades.
In SAS 3, they act somewhat the same as in SAS 2 and IA: the whole screen turns white and kills a lot of zombies. These are useful for thinning out hordes of zombies but ineffective for killing high powered zombies. Holy Hand Grenades have a large blast radius and can be a game changer at levels where focusing on killing enemies such as the Devastators are important. At later levels when there are swarms of zombies, this can be used to massively increase kill count and gain XP, while at the same time helping the team overall (if playing in multiplayer), making it easier to work together on higher level zombies. However, if one has many of them, they can effectively spam them to troll, keeping the screen white for long periods of time and preventing all players from seeing what is happening and where they are going. They are unobtainable on the Flash version, but available to use in the Mobile version of SAS 3.
- Beware when using these in any of the games during later levels. These will kill Butchers, but not the worms/parasites inside them. Because of this, large swarms of these worms/parasites will swarm after the player if they use a Holy Hand Grenade and there are multiple Butchers on-screen.
- The Holy Hand Grenade is a somewhat obscure reference to the Holy Hand Grenade of Antioch from the 1975 British comedy film Monty Python and the Holy Grail, of which it looks strikingly similar to.
- On a comedic note, when the Holy Hand Grenade is used, a loud "Hallelujah!" chorus will be heard, followed by (depending on the number of zombies when the grenade was used) a very loud spatter sound.