Srimad-Bhagavatam: Canto 3 - Chapter 1 - Verse 23
Sanskrit:
खरोऽश्वोऽश्वतरो गौर: शरभश्चमरी तथा ।एते चैकशफा: क्षत्त: शृणु पञ्चनखान् पशून् ॥ २३ ॥
ITRANS:
kharo ’śvo ’śvataro gauraḥśarabhaś camarī tathāete caika-śaphāḥ kṣattaḥśṛṇu pañca-nakhān paśūn
Translation:
The horse, mule, ass, gaura, śarabha bison and wild cow all have only one hoof. Now you may hear from me about the animals who have five nails.