Haos Tigrerra is the primary guardian Bakugan of Runo Misaki. Initially appearing as a quadrupedal, tiger-like entity with a primarily white color scheme, Tigrerra possesses a concealed internal blade capable of cutting any substance in the human world. Personality traits include fierce loyalty to Runo, protectiveness, a strong sense of duty, and a generally kind disposition. Runo affectionately nicknames the Bakugan "Tig". Tigrerra displays human-like qualities, experiencing confusion about human emotions and behaviors, while maintaining strategic thinking during battles. Significant development occurs when Tigrerra evolves into Blade Tigrerra during a critical battle against Lars Lion in the Doom Dimension, triggered by Runo's emotional confession. The evolved form stands bipedally, features numerous external blades across its body, and exhibits enhanced agility and tactical assessment. Blade Tigrerra gains the ability to judge optimal moments to strike opponents, utilizing sharp claws, fangs, and body blades in combat. Tigrerra's key abilities include "Cut in Saber" (adding itself to battles), "Cut in Slayer" (defeating the user's Bakugan to transfer their power), "Pure Light" (restoring defeated Bakugan), "Haos Freeze" (stopping battle time), and "Lightning Tornado" (modifying power levels). Blade Tigrerra utilizes "Velocity Fang" (nullifying opponent abilities and attribute gate cards), "Hyper Velocity Fang" (enhanced version negating abilities and reducing opponent power), "Saber Glosser" (transferring opponent power), "Metal Fang" (self-power increase), "Lightning Shield" (gate card nullification), and "Bolting Fang". During the New Vestroia conflict, Tigrerra is captured by the Vexos attempting to defend Mega Nemus against General Quasar and transformed into a statue displayed in Prince Hydron's throne room. This capture motivates the Legendary Soldiers of Vestroia to send Drago to Earth. Liberated later, Tigrerra participates in battles against Vestal invaders, including a confrontation alongside Magma Wilda against Macubass and Aluze. Expressing concern over the inability to evolve further like other Bakugan and the resulting danger to partners, Tigrerra and Hammer Gorem temporarily retire from active brawling. By Mechtanium Surge, Tigrerra has returned to New Vestroia, assuming a mentor role to Aerogan and wishing Runo and other brawlers safety. Tigrerra participates in the collective defense of New Vestroia against Mechtavius Destroyer, forming part of the final group destroyed alongside Aerogan during the assault. This fate is averted when the brawlers utilize the Current of Time to alter events. An inconsistency exists regarding the character's gender across media versions; the original Japanese portrayal presents Tigrerra as male ("Tigress"), while the English dub adaptation changes this to female, an adjustment also affecting Avior in subsequent seasons.