Rabio and Lepus are twin mechanical rabbits hailing from the world of Bunnyland. When their world is threatened by Yohmaoh and the royal family is kidnapped, the king of Bunnyland summons Rabio and Lepus to the rescue.
In Rabio Lepus and Sonic Wings, the pair appear to be sentient flying machines, while in later games, Rabio appears as the aircraft Aka Usagi. Both rabbits are white with colored ears, eyes, tails, and shoes. They both have buck teeth and wear yellow gloves. After receiving certain power-ups, they wear yellow ribbons on their right ears. Rabio's ears, eyes, tail, and shoes are red, while Lepus's are green.
Rabio is the red-eared 1P character in Rabio Lepus. After his appearance in Rabio Lepus, Rabio became one of the icons of Video System.
Rabio and Lepus are secret playable characters in the SNES version of Sonic Wings, unlockable via the following method: at the character selection screen, hold down the R button on the second controller, and enter the following code on the first controller: Left, Down, Right, X, Y, A, B, Left, Down, Right, Down, X, Y, A, B.
Neither Rabio nor Lepus has dialogue in single or two-player mode; instead they reveal another code, this one for unlocking a timed dog fight with the bosses of the game: at the character selection screen, hold down the R button on the second controller, and enter the following code on the first controller: A, Left, Y, Right, X, Down, B, Up.
After defeating all levels of the game with Rabio, or with Rabio and Lepus together, a sequence plays that shows Mao Mao waking up in bed, her arm around her Rabio plush. Once again, she has dreamed the events of the game, this time with her toy as the star. Mao Mao also has this plush in her own single-player end sequence, and Lord River-n-White has a black and white portrait of either Rabio or Lepus in his house during his end sequence.
Although Rabio and Lepus are not playable characters in any later games, they appear in cameos throughout the Sonic Wings series. In Sonic Wings 2, Rabio can be seen along with the game's bosses in the fair during the America stage. The Rabio Lepus video game is also visible in the ending sequence for Mecha-Keaton and Silver in two-player mode.
Rabio appears in the single-player mode end sequence for Mao Mao if the player fights the final boss battle against Lar. Similar to Mao Mao's ending in Sonic Wings, he is her plush toy. Also, Cincia is shown wearing a Rabio backpack in art for the game.
Rabio appears as a cursor on some menus.
Rabio appears in Pop'n Bounce as the final enemy, along with a blonde woman who is simply called "Lady."