I'll combine the next two and make this nasty little bugger - the stirge swarm. Looks fairly simple until you realize exactly how much Constitution damage this thing will be dishing out per round - I tried to be as 'realistic' as possible when determining abilities, but for survival purposes, I'd suggest limiting it to only a single attachment attempt on each PC per round of damage dealt, otherwise you have a lot of Con loss some really unfair deaths - the point is fast terror attacks and not brute power; a little bit of preparation on the part of mid-high level adventurers will knock one of these out of the sky pretty quickly. Other than that, this hasn't been playtested and I've never conjured a monster out of thin air like this, so I couldn't tell you how balanced or mechanically correct it is, not to mention all the inevitable copy/paste inconsistencies that may or may not need slogging through.
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A wealthy merchant has begun a shady logging operation on the edges of a swamp that borders several large farmland communities. Unbeknowest to the merchant, the townsfolk have made a pact with a lizardman tribe that inhabits the swamp, and by creating the logging operation, the merchant has violated it for the first time in a dozen generations. In retribution, the lizardmen have begun breeding stirges and sending them to attack the merchant's operation in large droves. However, their attacks are not only limited to the logging camp, and every few days a swarm will storm through a local town, sometimes feeding for hours before flying away. The townsfolk are baffled and panicked by the attacks, forced to barricade themselves indoors while watching friends and relatives who were caught outside drained of blood.
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Stirge swarm; tiny magical beast (swarm); CR 12 (?); HD 12d10; HP 66; Init +4 (+4 dex); Spd 10 ft., fly 40 ft. (average); Face/Reach 10 ft/0 ft.; SA attach, blood drain, distraction (DC 16); SQ swarm traits, half damage from slashing and piercing, darkvision 60', low light vision; AL N; SV Fort +8, Ref +12, Will +5 Abilities: Str 3, Dex 19, Con 10, Int 1, Wis 12, Cha 6; Skills: Hide +14, Listen +4, Spot +4; Feats: Alertness, Weapon Finesse
Attach (Ex): If a stirge swarm hits with a touch attack, one uses its eight pincers to latch onto the opponent’s body. An attached stirge is effectively grappling its prey. The stirge loses its Dexterity bonus to AC and has an AC of 12, but holds on with great tenacity. Stirges have a +12 racial bonus on grapple checks (already figured into the Base Attack/Grapple entry above). In addition, the stirge is separated from the swarm, and loses all swarm traits while attached, essentially becoming a normal stirge. The swarm is not affected by the loss, though the stirge can now be killed normally, though individually. An attached stirge can be struck with a weapon or grappled itself. To remove an attached stirge through grappling, the opponent must achieve a pin against the stirge.
Blood Drain (Ex): A stirge drains blood, dealing 1d4 points of Constitution damage in any round when it begins its turn attached to a victim. Once it has dealt 4 points of Constitution damage, it detaches and flies off, returning to the swarm to digest the meal. If its victim dies before the stirge’s appetite has been sated, the stirge detaches and returns to the swarm, seeking a new meal.
Swarm Traits: A swarm has no clear front or back and no discernable anatomy, so it is not subject to critical hits or flanking. The swarm takes half damage from slashing and piercing weapons. Reducing a swarm to 0 hit points or lower causes it to break up, though damage taken until that point does not degrade its ability to attack or resist attack. Swarms are never staggered or reduced to a dying state by damage. Also, they cannot be tripped, grappled, or bull rushed, and can only grappled by separating from the swarm – see rules under attachment. A swarm is immune to any spell or effect that targets a specific number of creatures (including single-target spells such as disintegrate), with the exception of mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects) if the swarm has an Intelligence score and a hive mind. A swarm takes half again as much damage (+50%) from spells or effects that affect an area, such as splash weapons and many evocation spells. For purposes of determining the effects of wind on a swarm, treat the swarm as a creature of the same size as its constituent creatures. A swarm rendered unconscious by means of nonlethal damage becomes disorganized and dispersed, and does not reform until its hit points exceed its nonlethal damage.
Distraction (Ex): Any living creature vulnerable to a stirge swarm’s damage that begins its turn with the swarm in its square is nauseated for 1 round; a Fortitude save (DC 16) negates the effect. Spellcasting or concentrating on spells within the area of a swarm requires a Concentration check (DC 20 + spell level). Using skills that involve patience and concentration requires a DC 20 Concentration check.
