Amoebic Crawler (CR 3)

Large Ooze (Extraplanar)
Alignment: Always neutral
Initiative: +0; Senses: blindsight

AC: 9 (-1 size), touch 9, flat-footed 9
Hit Dice: 4d10+32 (54 hp)
Fort +9, Ref +1, Will -4
Speed: 30 ft.
Space: 10 ft./10 ft.
Base Attack +3; Grapple +7
Attack: Tentacle +2 melee (1d6 plus 1d6 acid) or
2 tentacles +2 melee (1d6 plus 1d6 acid)
Special Attacks/Actions: Acid, improved grab, vile touch
Abilities: Str 10, Dex 11, Con 26, Int -, Wis 1, Cha 11
Special Qualities: immunity to electricity, ooze traits, translucent
Feats: -
Skills: -
Advancement: 5-12 HD (Large); 13-24 HD (Huge)
Climate/Terrain: Any
Organization: Solitary
Treasure/Possessions: Standard

Source: Dragon #330

Acid (Ex): An amoebic crawler's acid does not harm metal or stone.

Improved Grab (Ex): To use this ability, an amoebic crawler must hit with its tentacle attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and deals damage automatically every round (those grappled are affected by its vile touch ability).

Vile Touch (Su): Those grappled by the slimy tentacles of this creature sometimes glimpse images from the Far Realm, and the sight sends them into screaming, explosive convulsions of nausea. Each round a creature remains grappled, it must succeed on a DC 12 Will save or be nauseated for that round.

Translucent (Ex): Amoebic crawlers are hard to see, even under ideal conditions, and it takes a DC 10 Spot check to notice one. Creatures who fail to notice a crawler and walk into it automatically take acid damage.

An amoebic crawler attacks with its lashing tentacles, attempting to grab and slowly strangle helpless foes. Subdued foes are absorbed into the crawler's body in an horrific external digestive process.

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.