| Hit Dice: | 31d8+248 (387 hp) |
| Initiative: | +0 |
| Speed: | 60 ft. (12 squares) |
| Armor Class: | 21 (−8 size, +19 natural), touch 2, flat-footed 21 |
| Base Attack/Grapple: | +22/+46 |
| Attack: | Slam +27 melee (2d8+18) |
| Full Attack: | Slam +27 melee (2d8+18) |
| Space/Reach: | 30 ft./30 ft. |
| Special Attacks: | Greensickness, scoop, trample 2d8+18 (DC 37) |
| Special Qualities: | Airy, low-light vision, plant traits |
| Saves: | Fort +25, Ref +10, Will +10 |
| Abilities: | Str 35, Dex 10, Con 26, Int —, Wis 11, Cha 10 |
| Skills: | — |
| Feats: | — |
| Environment: | Tarterian Depths of Carceri (Cathrys) |
| Organization: | Solitary or tumble (2–4) |
| Challenge Rating: | 17 |
| Treasure: | Standard |
| Alignment: | Always neutral |
| Advancement: | 32–62 HD (Colossal) ♊ |
| Level Adjustment: | — |
An enormous ball of vines, easily the size of a building, tumbles toward you.
These monstrous, tumbleweedlike 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.
A plague brush has only one instinct: roll over things to flatten and kill them. The creature is not precise about accomplishing this goal, though. Once it rolls over an obstacle, it often ignores it thereafter. It’s not unusual for a plague brush to tumble through a camp or a community and simply keep on rolling by.
Greensickness (Su): A plague brush is continually surrounded by a cloud of spores in a 30-foot radius. The spores act as an inhaled poison (Fort DC 33); initial and secondary damage 2d6 Str and 1d4 Con. The save DC is Constitution-based.
Scoop (Ex): Any creature successfully trampled by a plague brush might be picked up and carried off with it. The plague brush can immediately attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple check, it picks up the victim and carries it as the plague brush moves.
In this manner, a plague brush can scoop up to 2 Huge, 8 Large, 32 Medium, 128 Small, or 512 Tiny or smaller creatures.
A creature scooped up by a plague brush is considered grappled.
Airy (Ex): Since a plague brush is constantly turning over and its anatomy is made up of a (relatively) small amount of plant matter and lots of empty space, it is difficult to know where to attack the creature. Any melee or ranged attack with a piercing weapon directed at a plague brush has a 20% miss chance. The blow or missile may pass through the creature’s body without harming it. Even a true seeing effect is useless for determining where and how to strike the creature.
In Eberron, the plague brush is not an extraplanar plant (and it loses the extraplanar subtype). Instead, it poses a danger to those brave, foolish, or desperate enough to venture into the Mournland. Created to weaken troops by means of their greensickness poison, plague brushes served as advance units in the Last War; now they randomly wander the stricken land.
In the Forgotten Realms campaign setting, plague brushes sweep across the Barrens of Doom and Despair. It is rare—but not unheard of—for these creatures to find their way onto other planes.
Source: Monster Manual III, page 124.