Crawling Head (CR 20)

Huge Undead
Alignment: Always chaotic evil
Initiative: +6 (+2 Dex, +4 Improved Initiative); Senses: Spot +35

AC: 12 (+2 size, -2 Dex, +6 natural), touch 8, flat-footed 12
Hit Dice: 28d12 (182 hp); DR: 35/epic
Fort +9, Ref +7, Will +20
Speed: 20 ft., climb 20 ft.
Space: 15 ft./10 ft.
Base Attack +14; Grapple +32
Attack: Bite +23 melee
Full Attack: Bite +23 melee and 4 tentacles +17 melee
Damage: Bite 2d6+10/19-20, tentacle 1d8+5
Special Attacks/Actions: Cacophony, constrict 1d8+5, improved grab, spell-like abilities, vorpal bite
Abilities: Str 30, Dex 7, Con -, Int 20, Wis 19, Cha 25
Special Qualities: Absorb head, electricity immunity, sonic immunity, SR 31, true seeing, undead traits, water vulnerability
Feats: Cleave; Combat Expertise; Great Cleave; Improved Critical (bite); Improved Disarm; Improved Initiative; Improved Trip; Power Attack; Spell Penetration; Weapon Focus (bite)
Skills: Climb +49, Concentration +38, Knowledge (arcana) +36, Knowledge (religion) +36, Search +36, Spellcraft +38 (+40 deciphering scrolls), Spot +35, Survival +4 (+6 following tracks), and Use Magic Device +38 (+40 scrolls)
Advancement: 29-56 HD (Huge); 57-84 HD (Gargantuan)
Climate/Terrain: Any underground or desert
Organization: Solitary
Treasure: Standard, double items

Source: Fiend Folio

The crawling head is a horrifying undead monstrosity spawned from the severed head of a giant. A crawling head's body is a huge, bloated giant's head that has grown to enormous size. Its jaws are overdeveloped and filled with multiple rows of sharklike teeth. A seething nest of animated intestines, arteries, and veins spreads out from the head's neck, allowing the creature to slither across any surface (even vertical ones) with surprising and disturbing grace. The creature's body is severed heads that it has swallowed, each one trapped in a sac just beneath the surface of the creature's translucent skin.

An overconfident necromancer who was quickly slain by his own creation created the original crawling head ages ago. Since then, crawling heads have been slowly increasing in number in areas frequented by giants and their ilk.

A crawling head can speak Common and Giant.