| vicious(adjective, mean, nasty, harsh, violent) |
| barbarous(adjective, animal, mean, hard, tough) |
| ferocious(adjective, animal, mean, nasty, harsh) |
| brutish(adjective, hard, nasty, violent, cold) |
| cold-blooded(adjective, mean, hard, tough, severe) |
| relentless(adjective, animal, mean, hard, tough) |
| inhumane(adjective, animal, person, mean, hard) |
| uncompassionate(adjective, animal, mean, hard, tough) |
| unforgiving(adjective, person, mean, hard, tough) |
| bloodthirsty(adjective, severe, nasty, harsh, violent) |
| inexorable(adjective, mean, hard, tough, severe) |
| stony(adjective, mean, hard, tough, severe) |
| cold(adjective, mean, hard, tough, severe) |
| murderous(adjective, hard, tough, harsh, violent) |
| unrelenting(adjective, animal, mean, hard, tough) |
| implacable(adjective, animal, mean, hard, tough) |
| insensitive(adjective, hard, tough, severe, harsh) |
| obdurate(adjective, mean, hard, tough, severe) |
| stony-hearted(adjective, cold, cruel, unfeeling, unsympathetic) |
| tough(adjective, hard, severe, sharp, harsh) |