Gargoyle blood

In the gargoyle hills, a tired adventurer huddled in his camp atop a hill. An early autumn storm had blown south from the mountains and the adventurer's mood soured as the wind whipped at his clothes.
"Perfect end for a miserable day." The adventure muttered, glaring up at the sky before turning the rabbit roasting over the fire.
"Eh, just call it quits and leave." The adventurer's wizened companion suggested, turning its red gaze to the adventurer and snapping its large teeth. "Just let the fae find a gargoyle himself."
The adventurer ran a hand through his light hair and looked at the redcap.
"Reid, you know I can't."
"Vander, you didn't make an oath. It'd be the human thing to do to leave." Reid motioned outward with his pike. "As much as I'd love to taste gargoyle blood, this quest has been a waste of time."
Vander shook his head as a light rain began falling. "The fae's supporting my best friend's efforts to build a kingdom. If Xylon can collect a vogiel's heart, then I can get some blood from a gargoyle." Vander checked the rabbit, and moved it off the flames.
"After three weeks, we haven't even seen a gargoyle!" Reid's face turned as red as his hat. "I'm getting tired of rabbit blood."
Vander moved his hand to feel the pouch hanging beneath his shirt, verifying that the vial containing a mixture of his and Reid's blood was still there. The redcap was a useful companion, but his loyalty would only last as long as the vial of their mixed blood remained in Vander's possession.
Vander knew that the moment it was gone, Reid would turn on him.
The rain fell harder as they ate the rabbit. Midway through the meal, a scraping sound climbed up the hill.
"What do you think?" Vander asked as the scraping sound grew louder.
"Could be a gargoyle." Reid's clawed fingers cut grooves in the bone he held. "Either that, or some other stone creature."
Setting aside the remains of his meal, Vander grabbed his mace and stood. Reid moved to join him, and they waited.
The creature's head appeared first. A leonine face contorted as the creature gave a gravelly snarl.
"Gargoyle?"
"Gargoyle."
Moving forward, Vander swung his mace at the gargoyle's head. The blow connected, a chips of stone broke off the gargoyle.
But there was no blood.
"Reid, make it bleed!" Vander shouted as the gargoyle snapped at the mace. Vander harried the gargoyle as the redcap moved into position.
"Bring it over." Reid called. Vander smacked the gargoyle once more, then turned and ran. The heavy pounding of the gargoyle sounded at his heels. Vander dropped into a slide on the rain-slicked grass as the hill slanted. He slipped beneath the lowered pike and just missed ramming into Reid.
There was a sickening thunk as the gargoyle rammed into the end of the pike; the redcap's magic allowing the weapon to pierce the stone flesh of the creature.
Vander stopped his slide and climbed back up the hill. Reid gave the pike a twist, and it tore free of the dead gargoyle. Gray blood poured from the wound, and the redcap was already drinking by the time Vander reached it.
"A vial full should satisfy the fae. You can have the rest." Vander said, though his companion gave no sign of having heard as the adventurer took out an empty vial and filled it with the gargoyle's blood.
As he tucked the vial away and headed back to his camp, Vander wondered what the fae wanted with gargoyle blood.