1. The White Mask: Tobi wears this mask initially due to his unstable condition. It represents his despair after Rin's death and his reliance on White Zetsu. He later wears it when persuading Nagato, showing his inner despair.
2. The Tiger Mask: This mask symbolizes Tobi completely breaking away from his former self. It first appears when Tobi attacks his teacher and his wife, leading to the deaths of Minato and Kushina. Tobi becomes Uchiha Madara, emotionless, aiming to create a new world.
3. The Whirlpool Mask: Wearing this mask, Tobi becomes a comical reserve member of the Akatsuki. However, his tone changes after Itachi's death. Tobi reverts to his original self, and the Whirlpool Mask represents his resilience for the Moon's Eye Plan.
4. The Rinnegan Mask: After Konan's attack, Tobi's Whirlpool Mask is destroyed. He obtains a Rinnegan eye, changing his mask's appearance to resemble the moon. This signifies his determination to unleash the Infinite Tsukuyomi and achieve his dream world. In the end, Naruto helps Tobi break through his mask of lies and illusions. Tobi reevaluates the world, rediscovers himself as Uchiha Obito, and strives to become the Hokage.