Nandī: Nandī, generally known as "Nandin", may be the identify of your bull that serves as Shiva's mount (Sanskrit: 'vāhana'). Shiva's association with cattle is reflected in his title Paśupati, or Pashupati (Sanskrit: पशुपति), translated by Sharma as "lord of cattle" and by Kramrisch as "lord of animals", who notes https://mahadev-booki.com/