How about a dragon how cheerfully rules over a kingdom; his people all know him for what he is, and dragons are looked upon as wise and benevolent creatures. Dragonslayers from other kingdoms coming to free it from 'tyranny' are likely to get beaten to death by peasants with cast iron skillets.
Someone needs the blood of a dragon, given willingly, to make a rare potion. Guess who gets hired to sweet-talk a dragon into giving up some highly powerful blood?
Idea from the Aeneid. Could make an intriguing encounter when searching for firewood..."Quite near there happened to be a mound of earth, at the highest part of which were growing thickets of cornel and a dense cluster of spiky myrtle-stems. I went up there and tried to wrench the green growth from the ground to provide a leafy covering for our altar. There I was confronted by a horrible and astounding miracle. For from the first bush which I tried to break off...blood oozed in dark drops, fouling the earth with its spots...A piteous moan came from the base of the mound and I heard a human voice answering me: 'Why, Aeneas, must you rend a poor sufferer? I am buried here...for I am Polydorus. Here death overpowered me in a crop of piercing iron-pointed spears. And so a crop resembling javelins has grown over me...'"