Rot Reaver (CR 6)

Medium Aberration
Alignment: Usually neutral evil
Initiative: +6 (+2 Dex, +4 Improved Initiative); Senses: darkvision 60 ft., Listen +6, and Spot +6
Languages: Common

AC: 19 (+2 Dex, +7 natural), touch 12, flat-footed 17
Hit Dice: 10d8+20 (65 hp)
Fort +7, Ref +5, Will +8
Speed: 30 ft., climb 20 ft.
Space: 5 ft./5 ft.
Base Attack +7; Grapple +9
Attack: +1 cleaver +11 melee
Full Attack: +1 cleaver +9/+4 melee and +1 cleaver +9 melee (1d6+2/x4)
Damage: +1 cleaver 1d6+3/x4, 1d6+2/x4 (off-hand)
Special Attacks/Actions: Cleaver mastery, rebuke undead 6/day (+3, 2d6+13, 10th), wound rot
Abilities: Str 15, Dex 14, Con 15, Int 7, Wis 12, Cha 16
Special Qualities: Animate dead, drain unlife, immunity to energy drain
Feats: Great Fortitude; Improved Initiative; Two-Weapon Fighting; Weapon Focus (handaxe)
Skills: Climb +10, Listen +6, Sense Motive +4, and Spot +6
Advancement: 11-20 HD (Medium); 21-30 HD (large)
Climate/Terrain: Any
Organization: Solitary or entourage (1 plus 1d4 human commoner zombies)
Treasure/Possessions: Standard plus two +1 cleavers

Source: Monster Manual III

Cleaver Mastery (Ex): A rot reaver's cleavers are identical in appearance to +1 handaxes - except that in a reaver's hands, these cleavers deal quadruple damage on a critical hit (rather than a handaxe's triple damage).

Rebuke Undead (Su): A rot reaver can rebuke undead as an evil cleric of 10th level. The creature can control any undead of 5 Hit Dice or less when it successfully affects the undead with its rebuke ability, and it can 4 command up to 10 Hit Dice worth of undead at any one time.

Wound Rot (Su): Any time a rot reaver damages a living creature with one of its cleavers in melee, it can immediately make a touch attack with one of its black, cancerous tongues (attack bonus +9). If the touch attack succeeds, the creature takes 1 point of Constitution damage and becomes vulnerable to the rot reaver's animate dead ability.

Creatures immune to ability damage are immune to this special attack.

Animate Dead (Su): As a standard action, a rot reaver can animate any dead creature within 60 feet that was affected by its wound rot ability within the last 24 hours. Creatures animated by a rot reaver rise as zombies.

A rot reaver can animate a number of Hit Dice of creatures equal to its own Hit Dice. Any attempt to animate a creature whose HD would cause this limit to be exceeded automatically fails. These animated undead are under the command of the rot reaver, and they do not count against the total number of Hit Dice of undead that a rot reaver can control using its rebuke undead ability.

Drain Unlife (Su): Any time a rot reaver damages an undead creature with one of its cleaver attacks, it heals a number of hit points equal to the damage dealt.

Immunity to Energy Drain (Su): Rot reavers are immune to energy drain attacks.

Skills: A rot reaver has a +8 racial bonus on Climb checks and can always choose to take 10 on Climb checks, even if rushed or threatened.

A brutal and formidable opponent, a rot reaver charges into battle and smashes its cleavers into its foes. Although it gains sustenance from undead flesh, a rot reaver's greatest joy comes from the destruction and reanimation of living creatures. Even the most voracious rot reaver is smart enough to preserve some of the creatures it animates as minions, and it sends these creatures into battle to soften up its opponents. If possible, a rot reaver will isolate one opponent, bring that individual down with the help of its undead minions, and then animate that foe immediately while its undead servitors move on to the next opponent.

When pressed, a rot reaver does not hesitate to use its drain unlife ability on its own undead minions, slashing away at the undead creature with its cleavers and gaining strength as it does so.