Werewolf

Lycantrophy is a curse that is spread through the bite of an already infected and turned werewolf. Infected humans turn into wolves during the next full moon and during every full moon afterwards. They cannot control their transformation and become bloodthirsty monsters, maiming and killing indiscriminately.
As wild beasts strongly tied to the full moon, werewolves are deeply connected with Cerawna - though some of her priests reject that connection for fear of casting their Goddess in a bad light in the eyes of common folk.

Weaknesses

Werewolves are notoriously hard to hurt, but they are vulnerable to silver. Touching silver for some time burns their skin and silvered weapons are the only known way to reliably kill a werewolf. Though many monsterhunters have stories about how "a bunch of smashing their head in does it in a pinch".