The Bowling Spin (ボウリングスピン) is the fourth mini-boss of Sonic the Hedgehog 3, fought at the end of Carnival Night Zone Act 1.
This mini-boss requires a fair bit of speed. The player will start out on a yellow and green-coloured square platform that will begin descending down the long shaft at high speed, and the boss will hover down from above. The little spiky top-like thing on its bottom will come off and start flying around the area, and it'll destroy one panel of the floor that it touches every time it comes into contact with it. So if the player lets it wear out the floor and they fall through, basically put, they're dead. While the spikes on the side are damaging, it's perfectly safe to stand on its flat top, and hitting it from below will redirect its path.
What the player needs to do is hit the actual capsule that the top was attached to and it'll reveal some of its circuits. The top then needs to hit the capsule while the circuits are revealed to do damage. The player should repeat this four times—rather than six with other mid-bosses—to finish it off. (It's only fair, since it's harder to hit than most mid-bosses.) Also, the capsule electrifies itself at random intervals. Obviously, the player should not jump at it at this point, except on top.
After the Bowling Spin's defeat, the remaining blocks will slow down and finally reach the bottom of the shaft, and the Signpost will fall from the top of the screen once the blocks have completely disappeared into the floor.