Riddick is an interesting comp too, but to me, Riddick was just such a pure receiver at the position whereas Kyren is a more natural runner to me.
I'd love to see Williams develop into a Westbrook type player, but Westbrook was so damn good in the receiving game that Williams has a long way to go there. Westrbook had four straight years over 600 yards receiving in the NFL with a 90 reception season on his resume too.
Regardless of the comp, I think we can all agree that Williams is one of the most exciting all-around running backs we've had in a long time.