As he always and by every means protects the creature of the universe and always find pleasure in their company and as he is the lord of them all, he is truly called Pasupati.
सर्वथा यत् पशून् पाति तैश्च यद् रमते पुनः। तेषामधिपतिर्यच तस्मात् पशुपतिः स्मृतः॥