Laudator Temporis Acti

Cicero, On the Republic 2.26.48 (tr. Niall Rudd):

As soon as a king takes the first step towards a more unjust regime, he at once becomes a tyrant. And that is the foulest and most repellent creature imaginable, and the most abhorrent to god and man alike. Although he has the outward appearance of a man, he outdoes the wildest beasts in the utter savagery of his behaviour. How can anyone be properly called a man who renounces every legal tie, every civilized partnership with his own citizens and indeed with the entire human species?

simul atque enim se inflexit hic rex in dominatum iniustiorem, fit continuo tyrannus, quo neque taetrius neque foedius nec dis hominibusque invisius animal ullum cogitari potest; qui quamquam figura est hominis, morum tamen inmanitate vastissimas vincit beluas. quis enim hunc hominem rite dixerit, qui sibi cum suis civibus, qui denique cum omni hominum genere nullam iuris communionem, nullam humanitatis societatem velit?

Oxford Latin Dictionary, s.v. vastus, sense 3.a (citing this passage):

Awe-inspiring by reason of size, force, etc.; (esp. of wild animals, superhuman beings, and sim.).