It's a gag item. And you're stuck with it forever. lol
Not a bad joke, but in the case of the protagonist's unlimited backpack, a pet Cheesy Weird Fish that occupies space may not be a bad thing. I hope to have some interaction in the future, just like Weird Fish eating worms
By the way, thank you for your suggestion. I finally figured out which step I missed. I didn't keep Cassie changing clothes(◡ ω ◡)
