i also want to vote apparel, but i'd really want it to be unique and a bit subtle that it's merch. i wouldn't want it to just be the official art plastered onto a shirt. haru from pokemon concierge wears a shirt that's a good example of this kind of subtle merch i'm talking about. like it looks like a generic hawaiian shirt but it's pokemon themed with oddish and bellossom. but i'm also concerned that something like that would be expensive and that the potentially high price would drive people away.
i'd also prefer merch of the pets than of the npcs! i'd love especially if they're plush keychains. if i can't have a jeweled unicorn in-game, i'll get one irl >:)