Yian kut ku

[Snowj_21]

Somebody else did the capture quest and then never sees the monster aggain? Some sort of bug? HR27 currently, no optional quest unlocked

[PurpuluDragon]

Hello,

Had the same problem, did a research and in another discussion, they have the answer (in case you still need it and since your the first to show up in my search result i'm going to repost the answer here in case someone else have the same problem) :
You need to do a quest that ask you to hunt a frenzied Yian Kut ku at HR 16.
A google search and you'll find the NPC to talk to.
Then it will unlock Yian kut ku quest (i found it on the map and use investigation, could hunt it three time, got enough for armor, but it didn't unlock the optional either, until you do that quest).