Swamp Troll

Swamp trolls resemble rock trolls but are taller, heavier and longer-fanged; duller, yet dangerously cunning. Unlike most trolls they live alone, adapted to life in pools, rivers, marshes and coastal waters. They breathe air (the appendix instead gives them water breathing), but enormous lungs let them stay submerged for a long time, and most prefer a cave full of air that can only be reached from under water, which they make safe by digging narrow air shafts that few other creatures could squeeze through.

Like all trolls they eat meat, killing almost anything and relishing human flesh. They also love treasure, not for its worth but because shiny things catch their eye, so one can sometimes be bought off. Long ago swamp trolls learned to lurk in the shade of bridges and charge travelers a toll, eating those who cannot pay. Most take over bridges built by men, but a few build their own; they are idle creatures, though they can make rough tools and weapons when they must. Kullervo the Wanderer lost one companion, and saw several more hurt, before his party killed a troll holding a bridge.

Where a family group lives together, killing its leader can set the rest on a vengeful rampage, so authorities often put up with a troll's raids rather than risk a reign of terror. They dislike sunlight and can bear the direct sun only briefly (the appendix says daylight does not affect them), so they stay in dark, shadowy places when they can, but will step out to face travelers when they have to. At least half of them can speak some human or humanoid tongue, though unlike other trolls they seldom mix with anyone but their own kind. They see by infra-vision. Most stand 7-9 feet tall, and exceptional ones reach the full nine feet.