Rakshasas Ambush the Monkeys but Are Slain
Ravana's followers—pishachas and rakshasas—attack the monkey army while remaining invisible. But Vibhishana knows their trick and strips their concealment away. The monkeys see them clearly, and the ambushers become the ambushed.
The monkey soldiers were quartered for the night, resting after the day's march. They did not know they were being watched.
Ravana had sent his followers ahead—pishachas (flesh-eating spirits) and rakshasas (demons) of considerable power. Their names were Parvana, Putana, Jambha, Khara, Krodhavasha, Hari, Praruja, Aruja, Praghhasa, and others. They crept into the camp invisible, their bodies hidden from sight, their weapons drawn. They intended to slaughter the monkeys while they slept.
But Vibhishana, the rakshasa who had abandoned his brother Ravana to join Rama, knew his former kin well. He knew their tactics, their tricks, their weaknesses. Invisibility was a favorite rakshasa strategy—strike without being seen, kill without being answered. Vibhishana had used it himself, once.
He did not shout a warning. He simply removed their power.
The invisibility fell away like a torn veil. The rakshasas stood exposed in the middle of the monkey camp, caught mid-stride, their weapons raised, their bodies suddenly visible.
The monkeys who could leap long distances—the strongest and fastest among them—saw the intruders and did not hesitate. They fell upon the rakshasas with the fury of warriors who had been nearly ambushed in their sleep. Parvana fell. Putana fell. Jambha, Khara, Krodhavasha, Hari, Praruja, Aruja, Praghhasa—all of them were killed by the powerful monkeys and fell down on the ground.
The ambush had failed completely. Not a single rakshasa survived to report what had happened.
But Ravana, back in his camp, learned of the slaughter anyway. He could not tolerate it. His followers had been killed before they could strike a single blow. The insult burned in him like fire.
He marched out with his entire army. Aranyaka Parva, Chapter 566