Ryoko's Guide to the Yokai Realms, pg 217
Frenzied, fanatical, and blisteringly fast, the wanyūdō is a fiendish yokai that takes the form of a large, flaming wheel. Your connection to it grants you the following benefits:
• Your speed increases by 10 feet.
• When you are prone, standing up costs you only 5 feet of movement.
• If you move at least 10 feet in a straight line towards a creature and are within reach of it, you can immediately use a bonus action to attempt a charging slam against that creature. Make a Strength (Athletics) check, contested by the target’s Strength (Athletics) or Dexterity (Acrobatics) check (target’s choice). Whoever loses the contest falls prone. You can use this benefit a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a short or long rest.