I have a Shadow the Hedgehog meme build I really want to play. He's a Tabaxi way of shadow monk. With unarmored movement and the mobile feat, my walking speed is 65ft at level 14. Feline agility, boots of speed and Haste (which I can get from an item or a friend) all double my speed, so I can get my walking speed up to 65x8=520ft (for a turn). On my turn I can move, dash as an action, dash as a bonus action (step of the wind), and dash as a hasted action for a total of 2080ft in 6 seconds. This is just over 380kmph, 8 kmph faster than the Formula1 record. Gotta go fast.