What is the rarest animal in Mope?

I'm curious, can you tell me what the rarest animal is in the game Mope? I've heard that there are some incredibly elusive creatures that players strive to find and capture, but I'm not sure which one is considered the most scarce. Could you elaborate on the characteristics of this rare animal and perhaps even offer some tips on how one might go about encountering it in-game? I'm genuinely fascinated by the concept of rarity in virtual worlds and would love to learn more about it in the context of Mope.