This is most definitely a literal use of the prompt, not a metaphorical one 🎃- a little bit of horror for you today.   

The manuscript had called it The Serpent, Hailey called it a dragon. Its body was long and sinuous, but the head was full of huge, sharp teeth.

She clutched her arm where its fang had landed a glancing blow. Blood glistened on its mouth as she backed away. This wasn't supposed to be how it went. She had the pendant, The Serpent was supposed to do her bidding.

"I command you!" she screamed.

"Myth," it hissed, shocking her into stillness.

"You spea..?" Her question became a burble of blood as the tip of The Serpent's tail erupted through her chest.

I hope you enjoyed my little offering today, thank you for visiting. See you tomorrow for more Halloween fun.