This story is inspired by the song Goodnight Demonslayer by Aurelio Voltaire. I heard it while I was in the hospital but now that I'm out I actually listened to the lyrics and just couldn't help but want to write a small fic about it.
Sam looked at his brother nervously. "What about the monster under my bed?"
Dean looked over at his younger brother, about to turn the light out and leave the room. "Sammy, your bed's a futon on the floor, he must be as flat as a board to live under your bed." Dean says, walking over to sit on the edge of the futon. "If he comes out to get you tell him you'll kick him in the nose."
Sam cracks a slight smile. "What about the creature behind the door?"
"I've checked fifteen times, there's nothing there." Dean assures him.
"No, he comes out when you leave," Sam said, small voice trembling.
Dean sighed and pet Sam's hair. "Sammy it's bed time…"
"But I'm scared," Sam responds.
Dean nods. "I know but you're safe, I'm here."
"What about the creature who eats children?"
"Tell him you taste bad, and if he eats you," he jumps towards Sam a bit, making the small boy jump, dean laughs. "Cut him open with your knife. And the harpies, tell them you'll roast them up."
Sam smiles crookedly. "Thanks Dean."
"Of course Sammy." he pets his brother's head gently and kisses his forehead. "Goodnight my little demonslayer."