Arachnophobia takes to the skies...

Feathered Widower

Type: Tiny Magical Beast
Hit Dice: 2d10+2 (7 hp)
Initiative: +3
Speed: 20 ft., climb 10 ft., fly 50 ft. (poor)
AC: 16 (+3 dex, +1 natural, +2 size)
BAB/Grapple: +2/-6
Space/Reach: 2-1/2 ft./0 ft.
Attack: Bite or pierce +7 melee (1d4-4 plus venom)
Full attack: Bite or pierce +7 melee (1d4-4 plus venom), 4 claws +2 melee (1d2-4)
Special Attacks: Envenomed Peck, Web
Special Qualities: Low-light vision, Tremorsense
Saves: Fort +4, Ref +6, Will +3
Abilities: Str 3, Dex 16, Con 12, Int 3, Wis 16, Cha 8
Skills: Hide +11, Sneak +11, Spot +9
Feats: Flyby Attack, Weapon Finesse(B)
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Environment: Warm or temperate forest, swamp or underground
Organization: Solitary
CR: 2
Alignment: True Neutral
Treasure: -
Advancement: -

A feathered widower is the result of hideous magical or alchemical expirements. The resulting beast is a creature that appears as a very large raven with an hour-glass shaped portion of striking red feathers upon its breast. Supporting it are eight legs with armored, chitonous scales growing out to the sides, with several taloned, gripping toes. Across the front of its head are four large, beady black eyes that gleam with an intense predator's look. Its long grey beak has a sharply ridged edge, with tiny holes lining it. A very large, feathery rump grows at its latter end with a pair of web-weaving spicules.

Feathered widowers are intensely devious creatures, to the point that they have a rudimenterary sentience that gives them a mighty edge in seeking their next meal. They are known for prefering dark recesses of castle towers, abandoned churches, or any other dark, large buildings. If none are to be found they take to massive trees, stringing their massive webs across the woods in the night.

Combat:
A feathered widower lies in wait for prey to pass by or get tangled in their webs, normally clinging to the sides of walls or trees. They will glide forward quickly, snapping at their prey, and then flapping away, awaiting them to be overcome by the venom within their beaks.

Envenomed Peck (Ex): Each bite of a feathered widower deals 1 point of temporary constitution damage unless making a DC 12 fortitude save. After half the points are drained the victim becomes Sickened until they are somehow regained.

Tremorsense (Ex): A feathered wdower can detect and pinpoint any creature or object within 60 feet in contact with the ground, or within any range in contact with its webs.

Web (Ex):
A feathered widower's web is a criss-crossing mass of insane design that it can stretch across entire acres at the tops of trees, using its powers of flight to go places a normal spider never could.
Approaching creatures must succeed on a DC 20 Spot check to notice a web; otherwise they stumble into it and become trapped. Attempts to escape or burst the webbing gain a +5 bonus if the trapped creature has something to walk on or grab while pulling free. Each 5-foot section has 4 hit points damage reduction 5/—.
An entangled creature can escape with a successful DC 12 Escape Artist check or burst the strand with a DC 16 Strength check.
The feathered widower can move across its own web at its climb speed and can pinpoint the location of any creature touching its web.

Skills:
A feathered widower gains a +8 bonus to its hide and sneak checks, and a +6 bonus on spot checks.

Fledgling Widower Swarm

A massive, dome-like object sticks to the side of this tree, appearing to be made out of many slick white strands with bushels-worth of feathers enwrapped within. A vague buzzing rises from within and tiny, bumblebee sized black birds zip towards you, beaks sticking out ahead like needles. Flashing their red breasts, they reach for you with eight tiny legs...

Type: Fine Magical Beast (swarm)
Hit Dice: 4d10+4 (24 hp)
Initiative: +8
Speed: 5 ft., climb 5 ft., fly 30 ft. (good)
AC: 26 (+8 dex, +8 size)
BAB/Grapple: +4/-
Space/Reach: 20 ft./-
Attack: (1d4 plus venom and wounding)
Full attack: (1d4 plus venom and wounding)
Special Attacks: Venom, Wounding
Special Qualities: Immune to weapon damage, Low-light vision, Tremorsense
Saves: Fort +5, Ref +12, Will +2
Abilities: Str 1, Dex 26, Con 12, Int 2, Wis 12, Cha 8
Skills: Spot +10
Feats: Flyby Attack(b), Hover(b), Weapon Finesse(B)
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Environment: Warm or temperate forest, swamp or underground
Organization: Single (1 swarm), Flock (2-6 swarms), Murder (10-16 swarms)
CR: 5
Alignment: True Neutral
Treasure: -
Advancement: -

Fledgling widowers are from the unlikely union of two feathered widowers. The female over the course of several weeks builds an egg sack made of her own webbing and feathers, and filled with the paralyzed bodies of other small birds and creatures light enough for it to carry which warm the tiny eggs and provide nutrients for the young once they hatch. A month or so after hatching the fledglings burst their way through the webbing, and still staying together, go forth in a swarming flock to hunt on their own.

Combat:
Fledling widowers surround larger prey, diving repeatedly and drawing blood and each giving tiny ammounts of poison that continuously weaken their meal. The swarm deals 1d4 points of damage to any creature whose space it occupies at the end of its move.

Tremorsense (Ex): A fledgling widower can detect and pinpoint any creature or object within 60 feet in contact with a surface they cling to.

Venom (Ex): Any living creature that begins its turn with this swarm in its space must succeed on a DC 11 Fortitude save or be nauseated for each round it remains within. The save DC is Constitution-based.

Wounding (Ex): Any living creature damaged by a fledling widower swarm continues to bleed, losing 1 hit point per round thereafter. Multiple wounds do not result in cumulative bleeding loss. The bleeding can be stopped by a DC 10 Heal check or the application of a cure spell or some other healing magic.

Skills: Fledgling widowers gain a +10 collective bonus on spot checks.

the feathered widower is a cr of one at most, probably one 1/2

A flying venomous creature who can trap things in webs and has tremorsense generally isn't a mere 1/2 rating creature