Hippos are vegetarians, and mean and territorial as all get out. That’s why I always found it amusing in the Jurassic Park movie when they portray brontosaurs as “kind of a big cow”. Big cow, indeed. If a 3 ton hippo is mean, imagine the attitude of a 30 ton dinosaur!
Rhinos and Cape buffalo are also vegetarians.
OTOH, most RINOs are carnivores.