The natural magic of the aranea has made its way into your ancestry, either in the distant past or in more recent generations. You sometimes feel the alien nature of the spider behind your own eyes and have a craving for blood, but how and when and why you hunt is up to you.
Class Skill: Climb.
Bonus Spells: disguise self (3rd), spider climb (5th), illusory poison (7th), vermin shape I (9th), phantasmal web (11th), mislead (13th), hold person, mass (15th), temporal stasis (17th), shapechange (19th).
Bonus Feats: Agile Maneuvers, Aspect of the Beast (prerequisites waived), Expanded Arcana, Lightning Reflexes, Silent Spell, Skill Focus (Knowledge [nature]), Stealthy, Vermin Heart (prerequisites waived), Wall Runner (prerequisites waived).
Bloodline Arcana: Vermin are susceptible to your mind-affecting spells. They are treated as animals for the purposes of determining which mind-affecting spells affect them.
Bloodline Powers: You gain strength as the spider stirs within.
The Blood Is the Life (Su): At 1st level, you can gain sustenance from the blood of the recently dead. As a standard action, you can drink the blood of a creature that died within the past minute. The creature must be corporeal, must be at least the same size as you, and must have blood. This ability heals you 1d6 hit points and nourishes you as if you’d had a full meal. You may use this ability a number of times per day equal to 3 + your Charisma modifier.
Nighteye (Ex): At 3rd level, you gain darkvision 30 feet. At 9th level, you gain darkvision 60 feet. If you already possess darkvision, its range is increased by these amounts.
Shroud of Vermin (Su): At 9th level, swarms no longer see you as prey. You can walk among swarms without fear of being harmed by them at all, and by taking a standard action to mentally command a swarm in which you stand, you can direct that swarm’s attacks and movements as long as you have more Hit Dice than the swarm. Even when you aren’t standing amid a swarm, your body crawls with vermin, and their chitinous bodies increase your natural armor bonus by +1. At 11th level, this bonus increases to +2, and at 17th level it increases to +3.
Venom Immunity (Su) and Freedom from Webs (Sp): At 15th level, you become completely immune to all poisons, mundane or magical, and are under a continual freedom of movement effect.
Death Spider (Su): At 20th level, once per day for a minute per level, you can increase your venom to a truly supernatural degree. When you attack with your fangs in a hybrid form or a spider form, you inflict 1 negative health level. Each negative level inflicted in this manner grants you 5 temporary hit points that last for 1 hour. The save DC to remove these negative levels is equal to 20 + your Constitution modifier. In addition, you are immune to level drain attacks for the duration.