This manga is about a moon demon fox that kills the 12, I believe, knights of the kingdom and the king. Goes on to revive one of the female knights and starts raising a baby after a dying castle courtesan convinced him to do so.
1 Answer
This is Clevatess: The King of Devil Beasts, The Baby and the Brave of Undead
It killed the heroes, killed the king, the devil beast then found the “baby of fate”... Having both superior intellect and destructive power, such is Clevatess, the king of the devil beasts. Angered by the 13 heroes tasked to take his life, he decided to bring ruin on mankind but get entrusted with an unexpected nuisance: a newborn human baby. Is it the tale of a near-ending world close to the apocalypse or the diary of new era childcare?
The story opens with a group of 13 heroes attacking the beast Clevatess; it's not very fox-like and is referred to as a "wolf" later on, but the "moonlight" part is mentioned.
The heroes are immediately killed by Clevatess. Annoyed, he goes to the nearby kingdom and destroys it after confronting the king and demanding an explanation, and not getting one. In the midst of the destruction a woman begs him to spare a baby. I don't believe it says precisely who she is; I assume she was a palace maid.
Clevatess agrees to care for the child, but has absolutely no idea how to do this or how humans work. He goes to the corpses of the 13 heroes and revives the most-intact one, a woman.
She is completely unable to disobey Clevatess due to the revival. He tasks her with caring for the baby, but as there is no baby food on the mountain he changes to a humanoid form and sets off for human lands to try to care for the baby.