"Is there anything preventing you from implying that monsters are simply exotic animals?"

"It wouldn't hold up to much questioning, I have the only winged cat in the world."

"Would monsters be well-described as minions of your world's variant of wild demons?"

"Yes, but they're generally not hostile once their progenitors die."

"That's not typical for wild demons here, but it's not particularly unbelievable."

"Well, I'm not going to offer him my cat, my cat is a person. I'm not sure how to balance - making it sound like another place on this planet, versus making it clear that he can have a menagerieful of monsters for the asking if he does portals for us."

"I don't think a menagerieful of monsters is in fact substantially better than one or two sorts of monsters, and may be worse, as it would seem less plausible to the Duke. I think we should aim to avoid it seeming so alien that it will frighten people, which means continuing to present it as a location on this planet, but that still leaves a reasonable amount of room. Especially given the.... lack of skepticism most people bring to claims about foreign locales."

"-did you say your cat was a person."

"Yeah, he can speak perfect English. He's my best friend. Most orphaned dungeon monsters aren't and don't turn into people but he did. The thing is I can just go catch a monster but all the specific monsters I know to exist have arrangements I can't necessarily pry them out of, so I can't guarantee any specific kind..."

"Are there general categories you could guarantee?"

"Not really. Most dungeons are new, with never-before-seen monsters and other features. I'm not aware of any recurring dungeons that are good sources of pets."

"Hmm... do you have any non-monster animals which we might not have?"

"Uh, I think we probably have fewer species but... better access to them? But also a lot of laws about exotic animals. I could maybe get him a... raccoon? And cross my fingers that nobody would miss a raccoon even if it might be technically unlawful to keep them without some kind of license."

"What are they like?"

"Catsize, gray with black markings - a mask over the eyes and rings on the tail."

"Are they well behaved?"

"No, not at all, they are not domestic animals. Maybe he'd like a tank of jellyfish, that'd be really easy and their behavior's not a factor."

"What are they?"

"Gelatinous brainless sea creatures, translucent, sort of a dome shape on top with tentacles. Some of them sting, like wasps."

"Oh, I believe I've heard of those but not by that name. You can maintain tanks of them?"

"Sure. He'd need to have a servant learn to maintain it, but you can have a tank of little jellyfish in your house if you want that."

"That seems like it would make a suitable gift -  are jellyfish uniquely suited to such tanks, or can you include other marine life?"

"I think jellyfish usually are kept by themselves but one can get a much more complicated fishtank with more going on if one wants."

"That would possibly be an even better option than jellyfish by themselves, especially if the tanks can be made large enough to function as the centerpiece of a party."

"Sure, though they're - stationary installations, if they're big."