The following is a menu of abilities available to all eidolons.

Armored Form. The eidolon gains a +3 bonus to the AC provided by its natural armor.

Acute Perception. The eidolon’s Wisdom score increases to 10 if it is not already higher, and it gains proficiency with the Perception skill. It applies double its proficiency bonus to Wisdom (Perception) checks and its passive Perception score, instead of its normal proficiency bonus.

Celerity. The eidolon’s walking speed increases by 20 feet.

Charge. If the eidolon moves at least 20 feet straight toward a target and then hits it with a slam attack on the same turn, the target takes an extra 9 (2d8) bludgeoning damage. It the target is a creature, it must succeed on a Strength saving throw (DC 8 + the eidolon’s proficiency bonus + its Strength modifier) or be knocked prone.

Claws. The eidolon’s appendages develop sharp claws, allowing it to make attacks with them. An attack with its Claws is a melee weapon attack. When the eidolon hits with an attack using its Claws, it deals slashing damage equal to 2d4 + its Strength modifier.

Energy Attacks. The eidolon’s appendages are wreathed in energy, dealing 1d6 extra damage when it hits with a melee weapon attack. This extra damage is of one of the following types: acid, cold, fire, lightning, psychic, or thunder, chosen when this ability is selected.

Energy Beam. The eidolon’s Charisma score increases to 16 and it gains the ability to fire a beam of coherent energy as a ranged power attack against one creature it can see within 60 feet of it as an action, using Charisma for the attack roll. On a hit, the beam deals 3d6 damage of one of the following types: acid, cold, fire, lightning, psychic, or thunder, chosen when this ability is selected.

Energy Resistance. The eidolon gains resistance to one type of damage from the following list: acid, cold, fire, lightning, psychic, or thunder. This ability can be taken twice, and the second time the eidolon gains immunity to the damage type chosen the first time this ability was taken.

Heightened Faculties. The eidolon’s Intelligence, Wisdom, and Charisma scores increase to 12 if not already higher, and it gains proficiency in Intelligence, Wisdom, and Charisma saving throws.

Improved Darkvision. The range of the eidolon’s darkvision increases to 60 ft.

Improved Function. The eidolon’s proficiency bonus increases from +2 to +4.

Massive Form. The eidolon’s Strength and Constitution scores increase to 18. Additionally, it becomes Large sized and its melee reach extends to 10 feet. If the eidolon is created with this ability through the manifestation of the project eidolon power and there is not a 10-foot cube of unoccupied space around the psicrystal, the manifestation of project eidolon fails.

Mighty Slams. When the eidolon hits with a Slam attack, it deals bludgeoning damage equal to 1d12 + its Strength modifier, and the target of the attack must succeed on a Strength saving throw or be pushed 10 feet. The DC is equal to 8 + the eidolon’s proficiency bonus + its Strength modifier.

Multiattack. The eidolon can use its action to make two melee weapon attacks.

Resilient Form. The eidolon's maximum hit points increase by 10. This ability can be taken more than once, increasing the eidolon’s maximum hit points by 10 each time.

Sinuous Shape. The eidolon has an elongated body, allowing it to make a Constrict attack as an action. A Constrict attack is a melee weapon attack. When the eidolon hits with a Constrict attack, it deals bludgeoning damage equal to 1d10 + its Strength modifier, and the target is grappled (escape DC 10 + the eidolon’s proficiency + its Strength modifier). Until the grapple ends, the target is restrained, and the eidolon can’t constrict another target.

The following is a menu of abilities available to eidolons that have acquired five or more abilities from the Lesser Eidolon Abilities menu. Some abilities from this menu require an eidolon to have an ability from the Lesser Eidolon Abilities menu before it can be selected.

Flight. The eidolon gains a flying speed of 60 feet.

Greater Energy Attacks. Prerequisite: Energy Attacks. The energy around the eidolon’s appendages intensifies, dealing an additional 2d6 damage when it hits with a melee weapon attack. This extra damage is of one of the following types, chosen when this ability is selected, and need not be of the same damage type chosen for the Energy Attacks ability from the Lesser Eidolon Abilities menu: acid, cold, fire, lightning, psychic, or thunder.

Greater Energy Resistance. The eidolon gains resistance to three types of damage from the following list: acid, cold, fire, lightning, psychic, or thunder. This ability can be taken twice, and the second time the eidolon gains immunity to the damage types chosen the first time this ability was taken.

Heightened Prowess. The eidolon’s Strength, Dexterity, and Constitution scores increase to 20 and it gains proficiency in Strength, Dexterity, and Constitution saving throws. This ability can be taken a second time, increasing the eidolon’s Strength, Dexterity, and Constitution scores to 24.

Impervious Form. Prerequisites: Armored Form, Resilient Form. The eidolon gains resistance to bludgeoning, piercing, and slashing damage dealt by nonmagical attacks. This ability can be taken a second time, granting the eidolon immunity to the above types of damage instead of resistance.

Improved Multiattack. Prerequisite: Multiattack. The eidolon can use its action to make three melee weapon attacks.

Inexorable Senses. The eidolon gains blindsight with a range equal to the range of its darkvision.

Perfect Function. Prerequisite: Improved Function. The eidolon’s proficiency bonus increases from +4 to +6.

Pounce. Prerequisite: Claws. If the eidolon moves at least 20 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a Strength saving throw (DC 8 + the eidolon’s proficiency bonus + its Strength modifier) or be knocked prone. If the target is prone, the eidolon can make another claw attack against it as a bonus action.

The statistics of a base eidolon, an eidolon before any abilities have been added to it, are given below. Following these base statistics, stats for a Shaper psion’s 1st-level eidolon are presented with all of its penalties already applied.

Following the above, statistics for sample eidolons created with the project eidolon power at power levels 3 through 9 are provided, each with the maximum number of abilities applied for each level. These are presented for ease of use, and represent only one possible combination of abilities for each level.