Blood Amniote (CR 9)

Huge Undead
Alignment: Always neutral
Initiative: +5 (Dex); Senses: blindsight 60 ft. and darkvision 60 ft.

AC: 26 (-2 size, +5 Dex, +13 natural), touch 13, flat-footed 11
Hit Dice: 10d12 (65 hp); DR: 10/-
Fort +3, Ref +8, Will -2
Speed: 30 ft., climb 20 ft.
Space: 15 ft./10 ft.
Base Attack +7; Grapple +18
Attack: Slam +9 melee
Full Attack: Slam +9 melee
Damage: Slam 2d6+6 plus blood call
Special Attacks/Actions: Blood call
Abilities: Str 19, Dex 20, Con -, Int -, Wis 1, Cha 1
Special Qualities: fast healing 5, inescapable craving, ooze traits, self spawn, undead traits
Feats: -
Skills: -
Advancement: 11-15 HD (Huge); 16-30 HD (Gargantuan)
Climate/Terrain: Underground
Organization: Solitary, pair, or amnion (4-8)
Treasure: None

Source: Libris Mortis

A clot of animate blood the size of a small house, this amoeba of failed life is hungry to add new blood to its oozing body.

The half-congealed blood of past victims gives a blood amniote its form, and its ties to the Negative Energy Plane give the creature animation. Mindless, it seeks only to pierce the fleshy carapace of all living creatures it comes upon so it can draw out the blood beneath.

Though these creatures are mindless, vestiges of past victims completely drained of blood remain imprinted on them. Observers sometimes see these random memories as faces that briefly form on the surface of a blood amniote, only to fall away again to formlessness moments later.