Bloodseeker SwarmCreature 3
Source Pathfinder #194: Cult of the Cave Worm
Perception +8 (darkvision, scent (imprecise) 60 feet)
Languages none
Skills Acrobatics +12, Stealth +12
Str -3, Dex +5, Con +1, Int -5, Wis +1, Cha -2
AC 20; Fort +6; Reflex +12; Will +6;
HP 36
Speed 10 feet (fly 30 feet)
Immunities precision, swarm mind
Weaknesses Area Damage 6, Splash Damage 3
Resistances Bludgeoning 3, Piercing 5, Slashing 5
Blood Draining Bites

Each creature in the swarm's space takes 1d6[piercing],1d6 bleed1d6 piercing damage plus 1d6 persistent bleed damage and is Drained 1. A successful DC 20 reflex save reduces the piercing damage by half and negates the bleed damage and drained condition.
Bloodseeker
Decades ago, the Court of Ether bred bloodseekers as show animals, thinking them adorably ugly. Generations later, the insects have become giantic. Visitors to the Court are impressed by how the bloodseekers to hover in place, fly through hoops, and only drink the blood of specific creatures.
Bloodseeker Swarm
The Court of Ether release the less useful, smaller breed of bloodseekers into the Endless Gulf, where they form into dangerous swarms of the insatiable devourers. This has lead to a dangerous new game, Seek-a-Bang, where fey mounted on giant bloodseekers throw thunderstones at swarms of their mounts' smaller cousins and see how many they can kill with a single throw. So far, the fatalities are few enough to be acceptable.
Bloodseeker Breeds
While the giant bloodseeker has the most notoriety for its size and use as a cavalry mount, other breeds have been created by determined ranchers. These including the longhaired bloodseeker, bloodseeker retriever, and the difficult-tocontain burrowing bloodseeker. Each of these recognized breeds can be submitted to the annual Court of Ether Bloodseeker Show, where breeders enter their prized, expensive, and well-trained bloodseekers in hopes of gaining the elusive "Best in Show" award.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
AnimalAn animal is a creature with a relatively low intelligence. It typically doesn't have an Intelligence attribute modifier over –4, can't speak languages, and can't be trained in Intelligence-based skills.
SwarmA swarm is a mass or cloud of creatures that functions as one monster. Its size entry gives the size of the entire mass, though for most swarms the individual creatures that make up that mass are Tiny. A swarm can occupy the same space as other creatures and must do so in order to use its damaging action. A swarm typically has weakness to effects that deal damage over an area (like area spells and splash weapons). Swarms are immune to the grabbed, prone, and restrained conditions.