Deities show their wrath in many ways—storms, earthquakes, volcanic eruptions, disease—but few means are as viscerally terrifying as a plague. Locusts that devour a nation's crops, hordes of rats that spread contagion— these are the so-called apocalypse swarms, the deadly messengers of angry gods.
An apocalypse swarm looks like a normal swarm of creatures until it engages in combat. Other creatures watching such a battle obtain a better understanding of what apocalypse really means—in witnessing the death of another being, they clearly see their own nearness to oblivion. Few can view another's death by such means and not find the experience chilling. Even creatures that were initially willing to stand firm and fight the swarm soon regret their bravery, for damaging such swarms only creates more of them. An apocalypse swarm grows in destructive capability, even as its foes succeed in diminishing its strength.
“Apocalypse Swarm” is an inherited template that can be added to any creature with the swarm subtype (referred to hereafter as the base creature). An apocalypse swarm uses all the base creature's statistics and special abilities, except as noted here.
Challenge Rating: As base creature +3.
Aura: An apocalypse swarm gains the fear aura universal monster ability with a range of 100 ft. Targets failing a Will save become frightened for 10 rounds; on a successful save a creature is only shaken for 10 rounds. The save DC is Charisma-based.
Hit Dice: An apocalypse swarm gains 5 racial Hit Dice beyond the base creature's total. Recalculate the swarm's base saves, hit points, feats, and skill points (if applicable), plus the save DCs for its special attacks.
When an apocalypse swarm takes its number of Hit Dice or more damage in a single attack, it splits into two identical swarms, each with half the original swarm's current hit points (rounded down). Attacks dealing less than 10 points of damage do not cause an apocalypse swarm to split due to its fast healing. Damage from multiple attacks is not cumulative in this regard. An apocalypse swarm reduced to 5 or fewer hit points cannot be split and disperses if reduced to 0 hit points.
Speed: All modes of movement double in speed. If the base creature can fly, its maneuverability doesn't change.
Attacks: An apocalypse swarm's melee attack damage increases by +2d6 (this includes an increase in swarm damage from the additional hit dice).
Special Attacks: An apocalypse swarm gains the following:
Any living creature that takes damage from an apocalypse swarm's swarm attack is nauseated for 1d4 rounds; a successful Fortitude save (DC 10 + 1/2 creature swarm's HD + creature swarm's Con modifiers) negates the effect. The save DC is Constitution-based. This ability replaces a swarm's distraction ability.
Abilities: Dex +4, Con +2.
Feats: An apocalypse swarm gains Ability Focus (greater distraction) as a bonus feat, in addition to new feats due to its increase in racial HD.
Skills: If the base creature has an Intelligence score, it gains skill points for its new racial HD as appropriate for its type. Assign these skill points as desired, treating skills on the base creature's list as class skills.