Bowser (SSBM)/Up special
Bowser retreats into his shell and starts spinning. A recovery move with very little start up. The attack has great knockback when used on the ground, and in the air, it is good for racking up damage. The attack hits once on the ground, but multiple times in the air. It's great for horizontal recovery, but does not cover much vertical distance. Can be used to grab the ledge quickly when grounded facing either direction.
The grounded version is one of Bowser's fastest and best moves, intangible from frames 1-4 and hitting starting on frame 5 (multiple hits until frame 46).