Let me start by saying that there aren’t a lot of cards I dislike to begin with. There are quite a few artworks that I find amazing; loads and loads of great/good artworks; also quite a few I don’t like that much (mostly the clay and cotton Pokémon; I still think the artists are very talented, but for cards I prefer hand-drawn more personally). Artworks I dislike is the smallest category for me in general.
However, there is only one artwork I still hate to this day:
Why? For years and years I thought this was what Larvitar looked like. I missed parts of the anime as a kid, so never seen Larvitar in it back then. It wasn’t until I came back to Pokémon near the end of 2015 and I re-watched all anime that I realized Larvitar actually looks like this instead:
Like wtf?! 
For all those years I always thought Larvitar was just a head like in that artwork. Kinda like Diglett partially burred in the ground, or perhaps more like Glalie (just a floating head). I’m still not 100% sure what I see in the artwork tbh… (Although I think Larvitar is looking at his own reflection in the water.) Sigh…
Greetz,
Quuador