Leech

Leeches were a species of segmented worms.

Description
Leeches were slimy and had a slug-like appearance.

Biology
Leeches were highly vulnerable to salt and the application of sufficient amounts could kill them.

Senses
Like many species of invertebrate, leeches had a set of ocelli in place of normal eyes. These were a group of light receptive cells that could register changes in light intensity, though not actual images. Because of this, giant leeches often reacted to changes in nearby light.

Combat
Leeches typically hid themselves within the mud or slime typical of their habitats, then waited to strike upon any warm-blooded creature that passed them by. Though sometimes feeding solitarily, they would sometimes group up into large swarms numbering up to two or five hundred members.

History
In the 14 century DR, Aurora's Whole Realms Catalogue was known to sell jars full of live leeches for 10 gp.

Sub-Species

 * Giant leech: A monstrous variety of the standard leech.
 * Throat leech:
 * Threeb: A variety of leech that was native to the jungles and swamps of the Abyss, such as the Gaping Maw and Slugbed.

Diet
These creatures fed upon the blood of warm-blooded creatures.

Habitats
Leeches were only known to be found in the waters of temperate swamps and marshes. In Faerûn, they were particularly known to inhabit the Vast Swamp, the Lake of Steam, and the jungle within the Cathedral of Emerald Scales. They were also quite prevalent in the marshes of High Moor.

Beyond Faerûn, they could be found in pools of water all throughout Chu' Yuan. During the summer season, swarms of them could be found in the lakes, rivers, and swamps of the Ama Basin. And in the Crowded Sea, they could be found on the island of Djinni's Claws.

Beyond the Prime Material plane, they could be found in the Para-Elemental Plane of Ooze.

Usage
Many peoples in the Realms would turn to the use of leeches when traditional medicines didn't prove effective. This belief was so widespread that they had somewhat of a placebo effect. Some even claimed they could be used to cure lycanthropy, though this was blatantly false.