Canto 3 -
Araṇya-kāṇḍa
Chapter 27: Rāma Kills Triśirā
Text 3.27.7

त्रिशिराश्च रथेनैव वाजियुक्तेन भास्वता।
अभ्यद्रवद्रणे रामं त्रिशृङ्गइव पर्वतः॥

triśirāś ca rathenaiva vāji-yuktena bhāsvatā
abhyadravad raṇe rāmaṁ triśṛṅga iva parvataḥ

triśirāḥ ca = Triśirā; rathena eva = chariot; vāji-yuktena = yoked with horses; bhāsvatā = [standing on] a dazzling; abhyadravat = rushed; raṇe = in battle; rāmam = towards Rāma; triśṛṅgaḥ = with three peaks; iva = resembling; parvataḥ = a mountain.

Resembling a mountain with three peaks, Triśirā, [standing on] a dazzling chariot yoked with horses, rushed towards Rāma in battle.1

1 Triśirā has been compared to a mountain with three peaks because he had three heads as it will be clear from text 17 in this chapter. His name literally means “One who has three heads.”