Universal Monster Rule

This attack saps a living opponent's vital energy and happens automatically when a melee or ranged attack hits.

The creature can engulf creatures in its path as part of a standard action.

The creature has an ability that restricts another creature's movement, usually with a physical attack such as ice, mud, lava, or webs.

A creature with fast healing regains hit points at an exceptional rate, usually 1 or more hit points per round, as given in the creature's entry.

The creature can use its swallow whole ability as a free action at any time during its turn, not just at the start of its turn.

A creature with ferocity remains conscious and can continue fighting even if its hit point total is below 0.

A creature with this ability can cease or resume flight as a free action.

The creature can hold itself so still it appears to be an inanimate object of the appropriate shape (a statue, patch of fungus, and so on).

This special quality makes a creature's very presence unsettling to foes.

A gaze attack takes effect when foes look at the attacking creature's eyes.

Creatures with grab can start a grapple as a free action without provoking an attack of opportunity, and receive a +4 bonus on combat maneuver checks made to start and maintain a grapple.

The creature generates so much heat that its mere touch deals additional fire damage.

The creature can hold its breath for a number of minutes equal to 6 times its Constitution score before it risks drowning.

Takes no damage and suffers no adverse effects from the indicated energy type, condition, or affliction.

Has no physical body; immune to nonmagical attacks, trip, grapple, and falling damage; gains Cha deflection bonus to AC.

The creature can swim backward as a full-round action at the listed speed.

The creature can notice other creatures by scent in a 180-foot radius underwater and can detect blood in the water at ranges of up to a mile.

The creature notices and locates living creatures within 60 feet, as if it possessed the blindsight ability.

Creatures with light blindness are blinded for 1 round if exposed to bright light, such as sunlight or the daylight spell.

Creatures with light sensitivity are dazzled in areas of bright sunlight or within the radius of a daylight spell.

A creature with low-light vision can see twice as far as a human in starlight, moonlight, torchlight, and similar conditions of dim light.

Natural lycanthropes can communicate and empathize with animals related to their animal form, gaining a +4 racial bonus on Diplomacy checks to alter such an animal's attitude.

The creature never takes penalties on its attack rolls when fighting with multiple weapons.

This ability is constant—the creature remains invisible at all times, even when attacking.