Happy is a fictional character from the manga and anime series Edens Zero, created by Hiro Mashima. He is depicted as a small, blue, anthropomorphic feline alien originally from the planet Excede. In a tragic event during his childhood on the planet Blue Garden, Happy was run over by a vehicle and killed. To save him, the scientist Professor Weisz Steiner transferred his consciousness into an advanced android body, effectively making him a cybernetic being. This new mechanical form is central to his identity and abilities. His design features a black-tipped tail, distinguishing him from his counterpart in Mashima's previous work.

Happy possesses a cheerful, loyal, and somewhat mischievous personality, often serving as a source of comic relief alongside his more action-oriented duties. He is deeply devoted to his lifelong partner, Rebecca Bluegarden, who gave him his name when she found him as an orphan. Their bond is the core of his character; he is fiercely protective of her and supports her ambitions without fail. Together, they run a popular online video channel called the Aoneko Channel, with their shared goal being to gain one million subscribers by uploading videos of their adventures across different planets. His primary motivation is to support Rebecca in achieving this dream while exploring the cosmos as a member of the adventurers' guild Shooting Starlight and, later, the crew of the spaceship Edens Zero.

In the story, Happy functions as Rebecca's best friend, partner, and primary weapon. His most notable ability is the transformation of his robotic body into a pair of blaster pistols known as the Happy Blasters, which Rebecca wields in combat. These weapons fire non-lethal rounds of energy called Ether bullets. As the series progresses, Happy demonstrates additional combat capabilities, including transforming into an assault rifle mode for increased range and power, generating a laser blade from his tail for cutting, and manifesting a cannon on his back for a solo barrage attack. His relationship with the captain of the Edens Zero, Shiki Granbell, is also key; the two become close friends soon after Shiki rescues Happy and Rebecca from a robot uprising on the planet Granbell. Happy also holds a deep gratitude toward Professor Weisz for saving his life.

Throughout the narrative, Happy undergoes a significant, if subtle, development regarding his state of being. While he appears to have accepted his cyborg body, the story explores alternate versions of reality. In the final story arc, the crew travels to a universe designated Universe Zero, where the events of Happy's past accident never occurred. In this timeline, he remains a flesh-and-blood biological cat, which consequently strips him of his ability to transform into weaponry, presenting a unique contrast to the android version that audiences have followed for most of the series.