Ethereal Marauder (CR 3)

Medium Magical Beast (Extraplanar)
Alignment: Always neutral evil
Initiative: +5 (+1 Dex, +4 Improved Initiative); Senses: darkvision 60 ft., Listen +5, and Spot +4

AC: 14 (+1 Dex, +3 natural), touch 11, flat-footed 13
Hit Dice: 2d10 (11 hp)
Fort +3, Ref +4, Will +1
Speed: 40 ft.
Space: 5 ft./5 ft.
Base Attack +2; Grapple +4
Attack: Bite +4 melee
Full Attack: Bite +4 melee
Damage: Bite 1d6+3
Special Attacks/Actions: -
Abilities: Str 14, Dex 12, Con 11, Int 7, Wis 12, Cha 10
Special Qualities: Ethereal jaunt
Feats: Improved Initiative
Skills: Listen +5, Move Silently +5, and Spot +4
Advancement: 3-4 HD (Medium), 5-6 HD (Large)
Climate/Terrain: Ethereal Plane
Organization: Solitary
Treasure: None

Source: Monster Manual


Once a marauder locates prey, it shifts to the Material Plane to attack, attempting to catch its victim flat-footed., The creature bites its victim, then retreats quickly back to the Ethereal Plane. When badly hurt or wounded, the marauder escapes to its home plane rather than continue the fight.

Ethereal Jaunt (Su): An ethereal marauder can shift from the Ethereal to the Material Plane as a free action, and shift back again as a move-equivalent action (or as part of a move-equivalent action). The ability is otherwise identical with ethereal jaunt cast by a 15th-level sorcerer.

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.