Source: Daughters of Fury, pg(s). 52
By some cruel twist of fate compared to other trolls, chimney trolls cannot heal their cursed wounds at all, unless it can consume the thing that other trolls loathe the most: fire. To fulfil this need, they skulk the rooftops of towns, hide in chimneys, and suck up the flames from the hearths of frightened folk. Their desperate reliance on fire has made them anathema to other trolls, who forced them to move from the wilds to cities.