I'm not the first to suggest it, but I would love an art gallery event.
Pets could be different art styles, inspired by real-life art styles and mediums (I know we already have a Monalisa themed, so that could be one of the npcs).


We've the recent 'unicorn in captivity' tapestry pet, that's another candidate
We could have pets covered in dripping paint (have you seen those pouring paints that are kind of popular right now? plenty of opportunities there). What about marble statue pets? Popart!
Background items like paintings, we could have foreground items be of different styles of frames (like the selfie frame from the internet event), backgrounds based off of real landscapes, maybe some dripping clocks? Starry night? Those squares Piet Mondrian is known for. Balloon animals are kind of in too, or you could have those as items.
New paintbrush items, paintbuckets, what about a clay turntable? Pottery in various stages of completion, including one that's gone floppy, in case your pet finds they're no good at pottery? How about some shelves to display art? How about some ridiculous price tags and evaluations? Glass blowing equipment?
Maybe we could be solving a painting theft mystery along the way, restoring paintings to the museum wall.
I just think there's a whole lot you could do with that.