Homunculus

take an egg laid by a black hen, poke a tiny hole through the shell, replace a bean-sized portion of the white with human semen, seal the opening with virgin parchment, and bury the egg in dung on the first day of the March lunar cycle. A miniature humanoid would emerge from the egg after thirty days, which would help and protect its creator in return for a steady diet of lavender seeds and earthworms.