Twitch is the only marksman that doesen't have a particle-changing skin
I know, I know. There are probably some better contenders for a skin right now than Twitch, but I wanted to point out that it feels kinda odd to me that he doesen't have any particularly good skin. When you look at them they generally look all the same with exception for Vandal and Pickpoket - he wears the same coat in every skin, and his fur is in different color, so in the end they don't change as much as you'd expect them to change. I find the whole thing pretty weird given how Riot totally nailed Twitch's indentity, including his VO and overall theme. You can argue with me, but I find Twitch one of the most unique and immersive champions in the league, next to champions like Kindred or Aurelion Sol. What has recently hit me the most, is that Lucian has got a Heartseeker skin over Twitch - you'd have imagined that Twitch could get one next to Quinn, since all of these skins had a common thing - shooting a hearty arrows from crossbows and bows. And there, you get a lovely shots coming out from a blasters, amazing. Im not saying here that the skin is bad, because it isn't - but from what I've been reading, Riot's comments hint that whether a champion gets a skin or not relies on not the overall number or quality of skins that they already have, but it relies on whether they can come up with a fitting skin theme/design for a champion or not. And that's what leaves me surprised, because I think that Twitch has a very wide field where coming up with good skin ideas doesen't seem hard.
Honourable mention - SSW Twitch is absolutely adorable, and doesen't follow the sinister look of other skins.