The Reputation Level just below Neutral and above Hostile.
Additional info:
- Unfriendly NPCs will not interact, talk, buy, sell or trade with you.
- When you click on unfriendly mobs or NPCs, their name and highlight will be orange. Unfriendly creatures will not attack unless attacked (or if you do other hostile things, like opening a box next to an unfriendly NPC).
- 3000 reputation points inside of being unfriendly.