Mnevis

Mnevis or Mer-wer was an aspect of the Atum-Ra, the chief god in the pantheon of Heliopolis. The origin and meaning of its name is currently unknown.
Mnevis was identified as being a living bull. This may be a vestige of the sacrifice of kings after a period of reign, who were seen as the sons of Bat or Hathor, the ancient cow deity of the early solar cults. Thus, seen as a symbol of the later sun god, Ra, the Mnevis was often depicted, in art, with the solar disc of their mother, Hathor between its horns.