The Crab Shaman embraces the spirit of the crab as a scavenger of the ocean floor and its shores. She roams the wrecks of ships and flotsam looking for bits of treasure and interesting items. The Crab Shaman is stubborn and greedy, once she grabs on she tends not to let go unless dead or unconscious.
Nature Bond: A crab shaman who chooses an animal companion must select a crab (see below). If choosing a domain, the crab shaman must choose from the Animal, Protection, Water, or Weather domains.
Wild Empathy (Ex): A crab shaman can use wild empathy with aquatic vermin (ex crabs, lobsters, crayfish) as a full-round action with a +2 bonus. A crab shaman may also use her handle animal skill on aquatic vermin as if they were animals with an INT of 1.
Totem Transformation (Su): At 2nd level, a crab shaman may adopt an aspect of the crab while retaining her normal form. She gains one of the following bonuses: movement (20 ft swim speed or +10 to swim speed if the shaman naturally has it), senses (darkvision 30ft), toughness (+2 natural armor bonus to AC, Endurance feat), or natural weapons (2 claws [1d4] for a Medium shaman, +2 to CMB on grapple checks, Constrict 1d4). While using totem transformation, the crab shaman may speak normally and can cast speak with animals (aquatic only) at will. Using this ability is a standard action at 2nd level, a move action at 7th level, and a swift action at 12th level. The crab shaman can use this ability for a number of minutes per day equal to her druid level. These minutes do not need to be consecutive, but they must be used in 1-minute increments. This is a polymorph effect and cannot be used while the druid is using another polymorph effect, such as wild shape.
Totemic Summons (Su): At 5th level, a crab shaman may cast summon nature’s ally as a standard action when summoning crabs (see below), and summoned crabss gain temporary hit points equal to her druid level. She can apply the young template to any crab to reduce the level of the summoning spell required by one. She can also increase the level of summoning required by one in order to apply either the advanced or the giant template, or increase it by two to apply both the advanced and giant templates. This ability replaces a thousand faces.
Wild Shape (Su): At 6th level, a crab shaman’s wild shape ability functions at her druid level – 2. Unlike standard druids, she may take on the form of a crab and instead uses her druid level + 2.
Bonus Feat: At 9th level and every 4 levels thereafter, a crab shaman gains one of the following bonus feats: Athletic, Endurance, Iron Will, Improved Iron Will Fortitude, or Toughness. She must meet the prerequisites for these bonus feats. This ability replaces venom immunity.
Crab Companion
Starting Statistics: Size Small; Speed 30 ft., Swim 20 ft; AC +5 natural armor; Attack 2 claws (1d3); Ability Scores Str 13, Dex 13, Con 14, Int -, Wis 10, Cha 2; Special Qualities Darkvision 60ft, Immune to Mind Effects, Water Dependency.
4th-Level Advancement: Size Medium; Attack 2 claws (1d4); Ability Scores Str +4, Dex –2, Con +2; Special Qualities Constrict.
Note: Giant Crabs have the drawback of water dependency. They cannot last out of water for more than CON hours. Care from the druid using the Create Water orison is recommended to keep their companion healthy.
Nature Summons (and wild shape uses):
Summon Nature's Ally II Crab, Giant (Medium size, replaces Giant Worker Ant)
Summon Nature's Ally IV Crab, Rock (Large size, replaces Giant Drone Ant)
Summon Nature's Ally VI Crab, Shark-Eating (Huge size, replaces Giant Scorpion)
Crab, Rock and Crab, Shark-Eating are found on the Pathfinder SRD website. Please read and comment, thanks!