The Hydra is a Legendary Air Ride Machine that appears in Kirby Air Ride. It can only be unlocked in City Trial. The player must either get all three parts from Red Boxes to ride it temporarily, or unlock all three parts on the Checklist to ride it in Free Run. It has very good turning, a fair glide, and high attack power that can defeat most other Air Ride Machines in one hit. It is one of the "legendary" stars (along with the Dragoon), and is one of the hardest stars to unlock. It possesses extremely high stats, surpassing the Dragoon in most areas except for handling and gliding, but its charging abilities are among the worst in the game. Similar to the Bulk Star, this star runs on "fuel" from charging (which takes a large amount of time). After a full charge, the Hydra will go at reckless speeds. It's an ideal vehicle for medium-length tracks, as the charge time will take too long in short tracks, and will take its toll on the user if the race is too long. If the spin attack is used in close range of an enemy, the Hydra will perform a ramming attack instead of a spin.
The Hydra's appearance is based on the rhinoceros beetle, an insect known for its strength. In fact, the Hydra is so powerful that at full speed, it can destroy most Air Ride Machines in one hit simply by ramming into them; the only Air Ride Machine that cannot be destroyed in one hit is the Wagon Star. The name probably comes from the seemingly invincible Hydra of Greek mythology, which is a possible reference to its durability.
One of only two legendary Air Ride machines. Known also as the King of Destruction, the Hydra was born to battle. Collecting its three parts on City Trial will reveal its fiendish side. With high offensive and defensive levels, the Hydra can easily blast through rivals and obstacles, leaving a swath of ruin. This is the ultimate Air Ride machine for attacking the course.”
Hydra is likely derived from the monster in Greek mythology of the same name, a multi-headed snake monster whose heads duplicated when cut off. This reference likely serves to emphasize the Hydra's enormous attack power and practical invincibility.
The item "Machine Parts", found in The Great Cave Offensive in Kirby Super Star Ultra, is actually the Hydra's wings, and it adds 121,300G to the player's score. Since Kirby Air Ride was developed after Kirby Super Star, it can't be found in the original game. In the original Kirby Super Star, the Machine Parts were instead the Nunchuks.
Regardless of the number of top speed patches the player may have obtained, the fastest the Hydra can go at any given time is 124.86 mph.