Checking the new guide https://www.speedrun.com/mkds/guide/jepmb which tells which are the best karts for snaking (and the stage to practice them https://www.speedrun.com/mkds/guide/atlq0), while also having watched Keverage's run at AGDQ using ROB which actually I was shocked (considering I was used to see some vods with either Dry Bones or Yoshi) triggered the question in the title.

:)

The character you choose does not really matter because they don't effect the stats of the car and I played as a few characters in the Egg 1 and I did not really notice a difference while driving or snaking. So it mainly matter if you choose a kart that can snake really good.

I assume you’re talking about 32-track speedrun since you mention Keverage.

Charaters affect weight, which affects offroad speed. Dry Bones is the lightest character and as such is the preferred choice, his speed offroad is the fastest. You get pushed around by CPU much more with light weight though, but unless that’s a really big deal for you you should just pick Dry Bones. If you’re PRBing then offroad won’t affect your speed so a heavier character can still keep up if you’re PRBing.

The best kart depends on your skill level. Entry-level is Dry Bomber, if you’re better you should use Egg 1. Polt and BLS might be better but they’re very hard to use so not recommended.

For Time Trials DB/E1/Polt/BLS are still the main karts but there can be some variety, you can check WR history at https://mkwrs.com/mkds/