SB 7.9.15

nāhaṁ bibhemy ajita te ’tibhayānakāsya-
 jihvārka-netra-bhrukuṭī-rabhasogra-daṁṣṭrāt
āntra-srajaḥ-kṣataja-keśara-śaṅku-karṇān
 nirhrāda-bhīta-digibhād ari-bhin-nakhāgrāt
Synonyms: 
na — not; aham — I; bibhemi — am afraid; ajita — O supreme victorious person, who are never conquered by anyone; te — Your; ati — very much; bhayānaka — fearful; āsya — mouth; jihvā — tongue; arka-netra — eyes shining like the sun; bhrukuṭī — frowning brows; rabhasa — strong; ugra-daṁṣṭrāt — ferocious teeth; āntra-srajaḥ — garlanded by intestines; kṣataja — bloody; keśara — manes; śaṅku-karṇāt — wedgelike ears; nirhrāda — by a roaring sound (caused by You); bhīta — frightened; digibhāt — from which even the great elephants; ari-bhit — piercing the enemy; nakha-agrāt — the tips of whose nails.
Translation: 
My Lord, who are never conquered by anyone, I am certainly not afraid of Your ferocious mouth and tongue, Your eyes bright like the sun or Your frowning eyebrows. I do not fear Your sharp, pinching teeth, Your garland of intestines, Your mane soaked with blood, or Your high, wedgelike ears. Nor do I fear Your tumultuous roaring, which makes elephants flee to distant places, or Your nails, which are meant to kill Your enemies.
Purport: 

Lord Nṛsiṁhadeva’s fierce appearance was certainly most dangerous for the nondevotees, but for Prahlāda Mahārāja such a fearful appearance was not at all disturbing. The lion is very fearsome for other animals, but its cubs are not at all afraid of the lion. The water of the sea is certainly dreadful for all living entities on the land, but within the sea even the small fish is unafraid. Why? Because the small fish has taken shelter of the big ocean. It is said that although great elephants are taken away by the flooding waters of the river, the small fish swim opposite the current. Therefore although the Lord sometimes assumes a fierce appearance to kill the duṣkṛtīs, the devotees worship Him. Keśava dhṛta-nara-hari-rūpa jaya jagadīśa hare. The devotee always takes pleasure in worshiping the Lord and glorifying the Lord in any form, either pleasing or fierce.