Pescavitus 2014
CR 1 celestial
Small celestial, neutral good
Its weapon attacks are magical. When it hits with any weapon does extra 2d4 radiant (included below).
Doesn't require food drink or sleep
Advantage: spell/magic effect saves.
When a creature reduces the pescavitus to 0 hp that creature is cursed for 5 days (DC 13 Cha negates). Cursed creature can be detected as a fiend with spells such as detect evil and good. In addition for the duration cursed creature gains only half the benefit of magic that restores hp and gains no benefits from finishing a long rest. A creature that consumes any amount of the flesh of a pescavitus is automatically cursed. Curse can be lifted by a remove curse spell or similar magic.
Can breathe only underwater.
Source: Tome of Beasts 3 (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details