The Owl

[Guywars]

I have the achievement for completing 5 of the king's challenges but i didn't unlock the Owl, is it bugged?

[Kasseth]

For me, it wasn't until I encountered the King several more times after the achievement that he mentioned to speak to him in the Breach, and gave the owl when I did so. Might be slightly bugged?

[Mr. Bubbles]

Nah, it's not bugged, you just need to amuse him a couple more Times because he is a ♥♥♥♥ ^^

[Guywars]

I just did it, you just have to talk with him in the gungeon after completing his challenge.

[thebiomage]

I didn't get the owl either after getting the achievement (tried talking to him in the breach too). Only after completing something like 10-15 King's challenges did he specifically tell me to speak to him in the breach, after which the owl unlocked. So yeah, seems to require more challenges completed than just the 5 the achievement requires.