Valmiki Ramayana Bala Kanda Sarga 24 Shloka 27

वृत्तबाहु: one who has round arms, महावीर्य: a highly energetic, विपुलास्यतनु: having large face and huge body, महान् gigantic, भैरवाकार: having dreadful form, राक्षस: rakshasa, नित्यम् always, प्रजा: inhabitants, त्रासयते frightens.

The arms (of Maricha) are round and strong. He is highly energetic. He has a large face and a huge body. In appearance, he is gigantic and possesses a dreadful form. That rakshasa always threatened the inhabitants.