The API for the Hungry Cat Scavenger Hunt appears to be bugged.
(see also: https://en-forum.guildwars2.com/discussion/72532/api-key-for-hungry-cat-scavenger-hunt)
I have the all but the Shattered Observatory Cat in my home instance and yet the API shows I'm missing the WvW ones and the Holokitty.
Hype is the path to the dark side. Hype leads to unfulfilled expectations. Disappointment leads to anger. Anger leads to disgust. Disgust leads to "oh, new shinies! I'm back!"