Creatures with the BUILDINGDESTROYER token will actively seek out various furnishings, workshops and other buildings and topple or destroy them. They come in two varieties, the first being annoying, and the second dangerous. Buildings made from raw materials will be toppled, leaving the materials on the ground, while buildings made from furniture will be destroyed, not leaving behind any items.
Creatures with this tag are gifted with an incredible ability to sense exactly where your buildings are. Underground creatures such as the Blind cave ogre or Voracious cave crawler will charge your fort immediately after spawning at the edge of the map. Plan your defenses accordingly. Building destroyers still prefer to attack creatures, and if a valid creature target for their aggression is or becomes visible to them, they will abandon building destruction in favor of classic creature destruction.
The time it takes for a building destroyer to destroy a building depends on the quality of the the building. Artifact quality furniture can never be damaged or destroyed, but some kinds of artifact furniture will be deconstructed by a building destroyer, given enough time: for instance, artifact statues will eventually be deconstructed; artifact hatch covers never will.
Building destroyers will destroy nearly all types of buildings they can reach, whether or not they block their path - doors, floodgates, hatch covers, vertical/horizontal bars, floor/wall grates, statues, workshops, and even furniture are vulnerable. The only buildings that will be spared by a building destroyer are wells, bridges, roads, traps (including levers and track stops), animal traps, chains, cages, stockpiles, and upright weapons. While they can destroy most furniture and buildings from a lower z-level when a valid path exists to that furniture, they cannot destroy hatches or grates from below. They can only destroy things orthogonally. Building destroyers will path to and destroy even opened (or stuck open) doors, hatches, floodgates, or vertical bars. They will cause damage to any attached mechanisms during building destruction, sometimes leading to the unlinking of furniture to a lever before the furniture in question is fully destroyed.
 Destroying from underneath
Building destroyers cannot destroy buildings unless their path to the building passes through the building's z-level. This means that building destroyers cannot destroy, for instance, a forbidden hatch above them (note that non-forbidden, i.e. passable, hatches are vulnerable!), or a magma forge from the magma underneath it.
Building destroyers can destroy buildings from the z-level below while standing on a ramp or stairs that leads up to the building's z-level.
 Annoying Variety
When the value is 1, the creature will go after statues, windows (glass or gem), archery targets, slabs, wooden doors, and wooden hatches. They can't destroy homes during world gen as (semi)megabeasts.
- Cave crocodile
- Giant cave spider
- Giant desert scorpion
- Giant olm
- Giant toad
- all Undead (unless it has [BUILDINGDESTROYER:2]), including ghosts
 Dangerous Variety
When the value is 2 the creature will actively seek out buildings and destroy them. They can also destroy buildings during world-gen with this tag. Megabeasts rely on this token for their pathing when attacking your fort. Constructions (walls, staircase, floors, etc.) are still safe, since they're processed the same way natural terrain is for most situations.
The simplest way to keep building destroyer 2's from targets is with walls or channels. The outside of a raised drawbridge will act like a constructed wall, blocking building destroyer 2's without that danger of being destroyed.
Tame animals still carry their building destroyer tokens.
- Amethyst man
- Blind cave ogre
- Bronze colossus
- Cave dragon
- Fire man
- Gabbro man
- Iron man
- Magma man
- Mud man
- Voracious cave crawler
- All forgotten beasts, titans, and demons
See the Modding guide for more information on creature tokens.