Limbo Stalker (CR 8)

Large Magical Beast (Chaotic and Extraplanar)
Alignment: Always chaotic neutral
Initiative: +2 (Dex); Senses: darkvision 90 ft., low-light vision, scent, Listen +3, and Spot +3

AC: 23 (-1 size, +2 Dex, +12 natural), touch 11, flat-footed 21
Hit Dice: 8d10+48 (84 hp)
Fort +12, Ref +8, Will +3
Speed: 40 ft.
Space: 10 ft./10 ft.
Base Attack +8; Grapple +19
Attack: Claw +15 melee
Full Attack: 2 claws +15 melee and bite +12 melee
Damage: Claws 1d10+7, bite 2d8+3
Special Attacks/Actions: -
Abilities: Str 24, Dex 14, Con 22, Int 2, Wis 12, Cha 10
Special Qualities: fast healing 5, immunity to electricity and fire, resistance to acid 5 and cold 5, limited invisibility
Feats: Multiattack; Track; Weapon Focus (claws)
Skills: Listen +3 and Spot +3
Advancement: 9-15 HD (Large), 16-25 HD (Huge)
Climate/Terrain: Ever-Changing Chaos of Limbo
Organization: Solitary, pair, or pack (3-5)
Treasure/Possessions: Double standard

Source: Planar Handbook

Limited Invisibility (Ex): Just as other predators use their environments as camouflage, a Limbo stalker is able to exert its will over its immediate surroundings in Limbo to conceal its own presence. By making a DC 16 Wisdom check as a free action, a Limbo stalker can wrap itself in an area of controlled Limbo so that it seems to vanish. If this check fails, a Limbo stalker can attempt the check once per round as a free action. Once a Limbo stalker establishes control, it need not check again. This effect ends the moment the Limbo stalker moves or attacks. It likewise ends if another sentient creature exerts control over the same area of Limbo and uncovers the limbo stalker.

Limbo stalkers have enormous amounts of patience and usually hunt by hiding somewhere near where their prey travels. Using their limited invisibility ability so camouflage themselves, Limbo stalkers wait for just the right opportunity to strike: a lone traveler, not paying any particular attention to his surroundings, and passing within 40 feet of a lurking Limbo stalker. The Limbo stalker then lurches out of its concealment, bull rushing the target into a solid object sometimes, the very ground that the target has shaped to stand on). Once the target is prone, the Limbo stalker launches a flurry of claw and bite attacks until the target, or the stalker, is dead.

When these creatures hunt in numbers, one Limbo stalker acts as the pack leader, by some understood agreement. In such cases, the pack attempts the same basic tactic, except that only one stalker (the leader) attempts the bull rush. The others come out of concealment only if the attack succeeds or if the target, in escaping, strays too close to one of the concealed stalkers to resist launching a second attack. Only when the target is dispatched will any Limbo stalkers still in concealment emerge to lope off with the others or help carry the prize.

A Limbo stalker's claw and bite attacks, as well as any weapons it wields, are treated as chaotic-aligned for the purpose of overcoming damage reduction.

Chaotic Subtype

A subtype usually applied only to outsiders native to the chaotic-aligned Outer Planes. Most creatures that have this subtype also have chaotic alignments; however, if their alignments change they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature has a chaotic alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the chaotic subtype overcomes damage reduction as if its natural weapons and any weapons it wields were chaotic-aligned (see Damage Reduction).

Extraplanar Subtype

A subtype applied to any creature when it is on a plane other than its native plane. A creature that travels the planes can gain or lose this subtype as it goes from plane to plane. This book assumes that encounters with creatures take place on the Material Plane, and every creature whose native plane is not the Material Plane has the extraplanar subtype (but would not have when on its home plane). An extraplanar creatures usually has a home plane mentioned in its description. These home planes are taken from the Great Wheel cosmology of the D&D game (see Chapter 5 of the Dungeon Master's Guide). If your campaign uses a different cosmology, you will need to assign different home planes to extraplanar creatures.

Creatures not labeled as extraplanar are natives of the Material Plane, and they gain the extraplanar subtype if they leave the Material Plane. No creature has the extraplanar subtype when it is on a transitive plane; the transitive planes in the D&D cosmology are the Astral Plane, the Ethereal Plane, and the Plane of Shadow.