Extra-Terrain (3.5e Creature Subtype)
From D&D Wiki
 Extra-Terrain Subtype
Extra-terrains are a species of alien that that arrive on unsuspecting worlds in the form of a meteorite. The meteorite is intelligent, and will guide itself to the nearest cavern system. It penetrates the earth, causing a massive hole. The meteorite stops when it reaches the cavern floor and immediately begins converting the atmosphere into a mixture of Hydrogen Sulfide, Ammonia and Methane. This initially affects a 30 ft radius, but this range doubles every night as the meteorite extends its influence. The organisms on the meteorite grow and evolve at an exceptional rate, eventually taking on forms that mock normal animals. The first recognizable form is a flatworm-like creature that is completely harmless and dies immediately if removed from its atmosphere.
Qualities: All extra-terrain creatures exhibit the following qualities unless otherwise noted.
- Oxygen Intolerance: Extra-terrain die if brought out of their natural atmosphere for more than one round.
- Fire Growth: If any extra-terrain is exposed to fire, a reaction within the creature is set off, forcing it to grow to enormous proportions. The creature immediately evolves into the next most powerful extra-terrain creature.
- Range: New form's occupied space.
- Save: Targets must make a Reflex save to avoid falling prone as they are knocked back out of the creature's growth space. Extra-Terrain creatures that fail their save are killed and absorbed.
- DC: 10 + New Form's HD + Con Mod
 Extra-Terrain Subtype Creatures
The following creatures have the Extra-Terrain subtype:
- Animated Pumpkin (3.5e Creature)
- Bowleg (3.5e Creature)
- Butthead (3.5e Creature)
- Canocroc (3.5e Creature)
- Carnivorous Plant (3.5e Creature)
- Drird (3.5e Creature)
- Extraterrestrial (3.5e Template)
- Flatworm (3.5e Creature)
- Giant Amoeba (3.5e Creature)
- Konkyah (3.5e Creature)
- Little Red (3.5e Creature)
- Mongrel (3.5e Creature)
- Razor Fish (3.5e Creature)
- Skitterer (3.5e Creature)
- Super Fly (3.5e Creature)