Plague Brush (CR 17)

Colossal Plant (Extraplanar)
Alignment: Always neutral
Initiative: +0; Senses: low-light vision

AC: 21 (-8 size, +19 natural), touch 2, flat-footed 21
Hit Dice: 31d8+248 (387 hp)
Fort +25, Ref +10, Will +10
Speed: 60 ft.
Space: 30 ft./30 ft.
Base Attack +23; Grapple +51
Attack: Slam +27 melee
Full Attack: Slam +27 melee
Damage: Slam 2d8+18
Special Attacks/Actions: Greensickness, scoop, trample 2d8+18
Abilities: Str 35, Dex 10, Con 26, Int -, Wis 11, Cha 10
Special Qualities: Airy, plant traits
Feats: -
Skills: -
Advancement: 32-62 HD (Colossal)
Climate/Terrain: Tarterian Depths of Carceri (Cathrys)
Organization: Solitary or tumble (2-4)
Treasure: Standard

Source: Monster Manual III

An enormous ball of vines, easily the size of a building, tumbles toward you.

These monstrous, tumbleweed-like plant creatures roll along the vast scarlet plains of Cathrys, the second layer of Carceri. A plague brush is often 35 feet wide and can weigh as much as 40 tons.

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.