Herbivore
An herbivore was any animal that ate only plants, such as fruits and vegetables. An herbivore was unlike a vegetarian in that it did not make the conscious choice to not eat meat. 

On Earth, the stegosaurus was a variety of dinosaur that was strictly a herbivore, of which fact Charles Tucker had to remind Malcolm Reed. ()

When captured by the Kzinti in 2269, the Chuft-Captain referred to Spock as an herbivore – an eater of "roots and leaves". Because of this classification, the Chuft-Captain refused to speak to Spock, and would only speak to Hikaru Sulu, because he at least ate meat. 

The Kzinti Telepath found it extremely difficult to read Spock's mind, because he could see images of Spock eating vegetation. ()

See also
Carnivore
Omnivore
Vegetarian

External link 
 

Lifeform classifications
Victual culture