Rapp is a member of the 0th Biotope
Not much is known about Rapp's origins but he is a member of the elite 0th Biotope and was noted as being particularly young for such caliber.
Rapp is a supporting protagonist created by Shimabukuro Mitsutoshi for the series Toriko.
Rapp's presence in the series has up to this point been limited. There is no apparent evolution to his character since his introduction.
Rapp is a very tall man, noticeably taller than Toriko and appearing about the same height as Zebra. He has a well built figure and has only been seen wearing an all red jump suit with white stripes, his helmet, goggles and grey boots with matching gloves. He has light skin and full lips, those being the only discernible features of his face.
Rapp is a respectful man but has been seen avoiding confrontation when Heavenly King Zebra threatened him yet also nearly instigating it when he accused Ryuu of possible treachery on baseless grounds. He remained silent however when Yosaku told him to shut up.
Mansam - Probably the only established relationship of Rapp's. He does not seem to be a friend necessarily, rather a loyal subordinate. However, Rapp is a member of the elite 0th Biotope under the direct leadership of President Ichiryuu. Whether or not he is ranked beneath Mansam is not distinctly clear.
After successfully capturing the Mello Cola, Toriko, Zebra and Komatsu celebrated at Komatsu's restaurant. They are interrupted by the arrival of Rapp, Mansam and Rei. Mansam orders the trio in an uncharacteristically blunt manner to hand over the corpse of the creature they had beaten and brought back with them from Gourmet Pyramid. Toriko asks what their reason for wanting it was, but Mansam would not answer him and told Rapp to handle the situation. At this, Zebra threatened to fight them, getting in Rapp's face. Mansam advised Zebra not to do so and that he would be no match for Rapp in a fight. Rapp, requested for Zebra to stand down as he preferred not to engage him in combat. He was confident that he would prevail but did not think he would get away unscathed. Zebra redirected his attention back to Mansam and said that he knew Mansam was lying about the situation since his hell ears could detect lies in speech. Mansam gave in and explained that the creature they had brought back with them from Gourmet Pyramid was a Nitro, an ancient creature with immense life-force and high levels of intelligence and battle prowess.
Rapp along with the entire 0th Biotope was present at the meeting held by President Ichiryuu, the exception being Master Chin Chinchin presumably due to his recovery from his injuries. During the meeting, Ichiryuu stated that there was a traitor in the group. Rapp was quick to suspect Former Gourmet Yakuza Boss Ryuu of being the rat and accused him without proof, but was quickly shut down by Saiseiya Yosaku who told Rapp to shut up and that he had personally recommended Ryuu and he was not the kind of man to be a traitor.
Rapp teamed up with Ryuu went to Sector E in the Gourmet World to capture one of Acacia's dishes before the Bishokukai did. Rapp and Ryuu are met by Niceny, the Aid to the Bishokukai Executive Chef, accompanied by several Nitro. After insulting the duo, Niceny expressed his disappointment that his opponents were only the two of them and not Ichiryuu himself. Later, Rapp is seen heavily injured and unconscious on the ground with a Nitro footprint beside him. He was presumably defeated by the Blue Nitro who had arrived after them. Whether Rapp survived or not is currently unknown.
Rapp's power scheme and Hunting method are currently unknown, but he is a member of the strongest Biotope, the 0th Biotope, formerly led by President Ichiryuu himself and having the likes of National Treasures among their ranks such as Chin Chinchin and Malisman. According to Chief Mansam, Zebra, regarded as the strongest Heavenly King at the time would have been no match for Rapp in combat.