Leech Blood is useful for fishing and can be efficiently farmed in swamp areas or bug caves with a strong mount such as a Megatherium or Quetzal. Use a ridden Araneo to safely remove leeches, and consider a wooden club for improved harvesting; infected leeches provide more blood. Leeches can be difficult to spot, so sweep through the swamp carefully with a mount capable of surviving its dangers, while some versions may also offer the resource through gift boxes.