Spanner

Also known as living bridges, spanners look exactly like big single-arch stone bridges, rails, posts and all. Each takes on the local stone color and stains, and grows vines or moss to match its surroundings. Telling one from a real bridge is extremely hard: only dwarves or someone with engineering or stonemasonry skill has a chance, and even then it takes an Intelligence or suitable proficiency check at -6.

Spanners would rather not fight. They are good-natured, even friendly, and far prefer swapping gossip and collecting news. Curious and clever, they put up with plenty of rough treatment as long as people keep talking. Annoy one, or cross without asking, and it turns spiteful and merciless. A victim within 5 feet of a rail gets heaved over the side; anyone else finds a hole opening beneath their feet. Either way a Dexterity check at -4 avoids falling. The fall deals 1d6 per 10 feet, to a maximum of 20d6, and a spanner over water may drown its victim as well. It senses foes by their weight on its deck or by ground vibrations out to 150 feet.

A spanner understands that animals need to cross and that a talking bridge would frighten them, so it lets wildlife pass in silence. It dislikes needless hunting nearby and automatically attacks anyone who hunts for sport and then tries to cross.

Being stone, a spanner has AC 0 and takes only half damage from edged or pointed weapons, though blunt ones do full damage. Once a day it can use a stoneskin-like ability that stops 8 attacks. Its Hit Dice depend on its length: 10 HD at 100 feet, plus 1 HD per extra 20 feet, up to 15 HD at 200 feet. A slain spanner just stops moving and becomes an ordinary bridge. It cares nothing for treasure; any valuables nearby belonged to its victims and are often broken by the fall or washed away by floods.

Spanners want to know about everything, and travelers can often buy passage just by chatting and sharing news, rumors and trivia, though the bridges themselves are tiresome gossips and frequent liars. They disguise themselves with stains, plants and local stone colors.

Nobody knows how they got loose. The usual theory is that a wizard bred them from mimics to guard the moats and gorges around his tower, and that they learned a great deal from his visitors, including how to walk. A spanner can push out pseudopods that take 4 rounds to become rough feet, letting it lumber along at movement 3. Most stay put for years but relocate if locals catch on or stop talking to them. Made of stone, they need no food, never reproduce and seem not to age.

A spanner is usually a blessing to the wild things around it, asking nothing of them and punishing anyone who abuses them.