Intended for use with Into the Odd, I present the Darkthing.
Art courtesy of ox3art
STR 14, DEX 10, INT 10, WIL 6, 14HP.
Bear-sized floating creature, cloaked in unnatural black smoke. No visible detail other than fleshy bubbles and lashing tendrils. Wounding it will give a flash of its true form, a pale creature with large eyes resembling a deep-sea fish. They attack without provocation but flee back into the ocean if badly hurt.
Its stinging tendrils cause an intense pain, attacking for 1d6 damage. Anyone that takes damage from them subtracts 5 from all rolls on their next turn as pain spasms strike their body.
The smoke around them fades when they are killed. Their corpses will also contain a thick chain each wears around their body. Trying to pick this up is painful, as they are intensely cold. May be safely picked up with leather or other thick material but over time will cause the material to stiffen and crack. Causes 1d6 damage per ten seconds of exposure to skin. Anyone who is knocked unconscious from this damage becomes a Darkthing themselves.