Bowser driving past a Puddle in his own city.
Puddles are an obstacle found in various raining courses. They function similarly to Oil Slicks.
Puddles are first seen in Mario Kart: Super Circuit in the course Luigi Circuit as an obstacle to avoid. Puddles are scattered around the course and driving into one will cause you to spin out so be careful! Puddles are also seen in Mario Kart DS's remake of Luigi Circuit.
Puddles are also seen around the futuristic Neo Bowser City in Mario Kart 7, Mario Kart 8, and Mario Kart 8 Deluxe. Here, they are located around various sharp turns especially near the course's end acting as an additional rough obstacle to avoid. Once again driving into a puddle will cause you to spin out and also drop 3 Coins.