Spawny

Spawny is a Rabbid that appears in Mario + Rabbids Kingdom Battle. In the Mushroom Kingdom, he is differentiated from other Rabbids by his white muzzle, blue belly, and ears, the fused SupaMerge headset that covers his eyes, and the on/off button on his lower back. His ability is to fuse other beings with Rabbids, doing so to create the Pirabbid Plant; however, said power is uncontrollable, and activates whenever he's stressed.

His name was given to him by Bowser Jr., who sought to use his powers to take over the Mushroom Kingdom. Although he is a major catalyst for the events of the game and forms an alliance with Bowser Jr., Spawny is not evil.

History
Spawny started out as an ordinary Rabbid, but when he and many other Rabbids were transported to an unspecified location, Spawny stole the SupaMerge and used it to fuse other Rabbids with objects, doing so to create Rabbid Peach and Rabbid Mario. When Spawny enters the Mushroom Kingdom, the SupaMerge ends up meshing with him, turning him into what he looks like throughout the game.

Beep-0 informs Mario that the SupaMerge had been corrupted upon entering the Mushroom Kingdom, and he agrees to find Spawny. However, just as Mario and co. were about to catch Spawny on a tower overlooking Ancient Gardens, Bowser Jr. appeared and befriended Spawny. Mario and co. traversed the other three worlds and eventually defeated Bowser Jr. in his mech, Mecha Jr., retrieving Spawny in the process. However, the portal over the Mushroom Kingdom released a dragon named the Megabug, which captured Spawny and harnessed his power to unleash more beings. Mario and co. ended up defeating the Megabug and freeing Spawny and Bowser (who had also been corrupted by the Megabug). Spawny is then seen in the pre-credits scene, where he admires the statue erected in honor of Rabbid Peach.

Personality
When he was still a regular Rabbid, Spawny was mischievous, curious, and playful like his fellow Rabbids, while always causing trouble without thinking about the consequences. After his transformation, Spawny became timid, naïve, and childlike. This causes Bowser Jr. to take advantage of him, bullying him into using his abilities. Because his power comes from fear and stress, Spawny has little to no control of his abilities.

Relationships
Bowser Jr.: Upon seeing Spawny's abilities, Jr. decided to use Spawny for his personal gain in order to defeat Mario and co, and make his father proud. After giving him his name, Jr. preyed on Spawny's naïve personality in order to befriend him. The little Rabbid shortly learned that Bowser Jr. was just using him and made several attempts to get away from him. Despite all that, Bowser Jr. generally does care about Spawny, showing concern when he fell out of his clown car and even scolding at Mario and co. when he was kidnapped by the Megabug. After Spawny was safe, thanks to Mario and co. Jr cause Spawny and gave him to the heroes, relieved that the young Rabbid was safe.

Mario, Luigi, Princess Peach, and Yoshi: Due to being overwhelmed by his power, Spawny was uneasy around Mario and friends, fearing that they were his enemies. He was startled when Luigi accidentally scared him causing him to create the Pirabbid Plant. Throughout the game Spawny grew uneasy around the heroes causing more stress, but eventually came to realize they wanted to help. After the battle with Mecha Jr. Spawny fell out of the clown car and was saved by Yoshi. After being rescued from the Megabug, Spawny eventually befriended the group and settled down. He seems to be the closest with Princess Peach as his trophy shows her hugging him while he smiles, and she even holds him during the unveiling of the Rabbid Peach statue. In an artwork of them, Spawny was giving the princess a holographic mustache much to her surprise.

Rabbid Mario, Rabbid Luigi, Rabbid Peach, Rabbid Yoshi, and Rabbids: Before his transformation, Spawny treated his fellow rabbids with compassion and mischief. After his transformation, he became timid and shy around them, possibly from the stress of his new powers, trying to avoid them so he wouldn't hurt them. With the heroic rabbids, he was afraid of them because he thought they were his enemies, but eventually warmed up to them seeing them as his friends.

Trivia

 * Spawny's mask is meant to be a reference to the Studio Ghibli film .