Enemy NPC (mob)

[Yukkurirumia]

Something like random Youkai appearing at night as like another mob, probably less HP than a zombie and does 1 1/2 hearts to non-armor.

Would be beneficial as a new enemy to experience since the only thing that would probably kill you in the wild would be mobs in general swarming you, arrow spam, or being trapped.

[WriggleRid3r]

Oooh, maybe difference level of youkai in different places? Maybe more dangerous ones in one biome than another?

[Ibuki Suika]

The problem with custom mobs is that it would require a mod for players to install as well as installing on the server, otherwise players would be unable to join the server.