Sinding

 is a werewolf Hircine punished by stopping him from returning to his original form. He is imprisoned in the jail of Falkreath.

Interactions
Upon speaking to Mathies, he explains that Sinding killed a little girl while transformed into a werewolf. The girl was the daughter of Mathies and Indara Caerellia, who both live at Corpselight Farm in Falkreath.

He was in Falkreath because he was looking for a giant beast roaming the wilds around the village. If he killed this beast, the Daedric Lord Hircine would lift his curse.

During "Ill Met By Moonlight", the Dragonborn receives the Cursed Ring Of Hircine from Sinding, which causes the wearer to sporadically transform into a werewolf. The transformations only occur if the Dragonborn is already afflicted by Lycanthropy and the ring cannot be removed until the quest is completed.

If the Dragonborn kills Sindling and take his skin, Hircine appears again to award him or her with the Saviour's Hide and also removes the Cursed Ring Of Hircine from the inventory. If the Dragonborn kills the hunters, however, Hircine appears and un-curses his ring, freely allowing to transfrom into a werewolf at will.

Quests

 * Ill Met By Moonlight

A.I.

 * If left to live he can be encountered every month at lest once at cleared bandit camps feeding on corpses (maybe possible to find him fighting some bandits in the fort in the overworld but the forts inside have to be cleared) or Helgen fighting bandits (and usually immortal by npc hand but one shotted by player because of being always low on hp - possible bug)
 * Have seen Sinding come to Dragonborn's aid when a dragon was attacking Falkreath.
 * If let live and run across him later you can still kill him and skin his hide for Saviour's Hide.
 * ChillrendBugAndWWMeeting.jpg