What do you think about Dunsparce’s enduring appeal despite it’s arguable uselessness?
I’m a big Dunsparce fan myself, and honestly it’s hard to separate how much of that is appreciation for a legitimately neat Pokémon and how much is purely a nostalgia thing. Dunsparce was a cool Pokémon in generation II; it was really rare, and as a kid with no independent internet access in 2000, it was pretty easy to just not know about it until I found one, after I’d already been playing the game for weeks and seen most of Johto (I don’t think there are any AI trainers in the original Gold and Silver that use a Dunsparce; unless you find one by sheer chance, your first hint at their existence comes from a phone call alerting you to a swarm). Almost every time I started a new game on Silver, I made time to stumble around Dark Cave until I found a Dunsparce to catch; sometimes I still do on Soul Silver for old times’ sake.
Aside from any nostalgia value, though, Dunsparce is just a really interesting design. It’s based on a creature from Japanese folklore and urban legend, the tsuchinoko (Dunsparce’s Japanese name, Nokocchi, is an anagram of tsuchinoko – the tsu character can be “silent” and have the function of doubling the next consonant). The tsuchinoko is an unusually plump and flat-bodied snake that, instead of slithering, moves by rolling (hence Dunsparce’s Rollout) or even jumping (hence Dunsparce’s wings and limited flight), and in some stories is able to speak. Dunsparce takes the idea and runs with it, but because there’s not really a “canonical” interpretation of what a tsuchinoko looks like or what it’s capable of, there’s a lot of room for Dunsparce to just add fun little quirky features like the stumpy wings and the drill tail that kind of fit, but give it independence from its origin. It’s creative, charming, weird, what’s not to like?
Dunsparce may be… well, let’s say “use-impaired,” but Serene Grace makes it pretty interesting, with several moves that are otherwise rarely seen (Headbutt, Body Slam, Zen Headbutt, heck, even Ancient Power; in single-player Secret Power is pretty fun) forming a part of its skillset, and I think there’s a bit of a sense that it would be all right if only it were given an evolution or something. It’s not a good Pokémon by any means, but at least you can tell that what it’s trying to do is interesting. I think Game Freak have largely gone off the idea of designing new evolutions for old Pokémon, and in any case it’s hard to come up with an evolution concept for Dunsparce that remains true to its origins as a weird, dumb, fat snake while keeping its unique charm, but if they did I think there’d be plenty of room to give Dunsparce a distinctive fighting style, and maybe create a mechanically interesting signature move to pull together its identity (see also here).