Hanuman assumed Panchamukhi or 5-faced kind to eliminate Ahiravana, a powerful rakshasa black-magician and practitioner of your dark arts in the Ramayana war. Ahiravana, brother of Ravana, had taken Lord Rama and Lakshmana to netherworld as captive, and the only way to kill him was to extinguish 5 lamps burning https://www.facebook.com/share/1J6iVuTuXb/