Blightspawned Treant* (CR 9)

Huge Plant
Alignment: Always neutral evil
Initiative: -1 (Dex); Senses: Listen +7 and Spot +7

AC: 20 (-2 size, -1 Dex, +13 natural), touch 7, flat-footed 20
Hit Dice: 7d8+42 (73 hp); DR: 10/slashing
Fort +11, Ref +1, Will +6
Speed: 30 ft.
Space: 15 ft./15 ft.
Base Attack +5; Grapple +24
Attack: Slam +14 melee
Full Attack: 2 slams +14 melee
Damage: Slam 2d6+11
Special Attacks/Actions: Animate trees, blight touch, create spawn, double damage against objects, trample
Abilities: Str 33, Dex 8, Con 23, Int 12, Wis 14, Cha 10
Special Qualities: fire vulnerability, plant traits, undead transformation
Feats: Improved Sunder; Iron Will; Power Attack
Skills: Diplomacy +2, Hide -9, Intimidate 4, Knowledge (any one) +6, Listen +7, Sense Motive +7, Spot +7, and Survival +7
Advancement: 8-16 HD (Huge); 17-21 HD (Gargantuan)
Climate/Terrain: Any land
Organization: Gang (2-5)
Treasure/Possessions: None

Source: Unapproachable East

The sample blightspawned presented here uses a treant as the base creature.

Animate Trees (Sp): This blightspawned can animate trees within 180 feet at will, controlling up to two trees at a time. It takes a full round for a normal tree to uproot itself. Thereafter it moves at a speed of 10 feet and fights as a treant in all respects. Animated trees lose their ability to move if the treant who animated them is incapacitated or moves out of range. The ability is otherwise similar to liveoak as cast by a 12th-level druid.

Blight Touch (Su): For this blightspawned, the Fortitude save DC to resist the blight touch is 19.

Create Spawn (Su): An animal, beast, or plant infected by this blightspawned's blight touch becomes a blightspawned itself if its Charisma reaches 0 before its Constitution does.

Double Damage Against Objects (Ex): This blightspawned or an animated tree that makes a full attack against an object or structure deals double damage.

Trample (Ex): As a standard action, this blightspawned or animated tree can trample opponents at least one size category smaller than itself. This attack deals 2d12+5 points of bludgeoning damage. A trampled opponent can attempt either an attack of opportunity at a -4 penalty or a Reflex save (DC 20) for half damage.

Fire Vulnerability (Ex): This blightspawned takes half again as much (40%) damage as normal from fire, regardless of whether a saving throw is allowed, or if the save is a success or failure.

Plant Traits (Ex): This blightspawned is immune to poison, sleep, paralysis, stunning, and polymorphing. It is not subject to critical hits or mind-affecting effects. It also has low-light vision.

Undead Transformation (Su): Each month of a blightspawned treant's existence, it must succeed at a Fortitude save (DC 11 + 1 per previous saving throw attempted) or die.

Skills: This blightspawned receives skills as though it were a fey. It has a +16 racial bonus on Hide checks made in forested areas.