One of the final chapters of Demon Slayer shows Kanao holding Iguro’s pet snake. Why did Iguro give Kanao his snake?
Iguro does not directly give his snake to Kanao. The Wind Hashira picks up the snake after Iguro falls in battle, and he gives the snake to Kanao at a later time.
Kanao explains to Tanjiro that the Wind Hashira is the person who gives her Iguro’s snake.
Iguro does not directly give Kanao his snake
In chapter #204, three months have passed since the final battle against Muzan. Overall, Demon Slayer does have a good ending. The Demon Slayer Corps successfully banishes all demons from the world, at the cost of heavy casualties.
Tanjiro, Inosuke, Zenitsu, and Kanao survive the battle. Amongst the Hashira, only Giyu, the Water Hashira, and Sanemi, the Wind Hashira, have survived.
Some of the survivors suffer long-lasting injuries to their bodies. Tanjiro’s arm has aged to that of an old man, and Kanao has gone mostly blind. The two remaining Hashiras are in decent shape, albeit shaken up from the battle.
After resting in bed and catching up with various guests, Tanjiro steps outside to see Kanao admiring a tree. She invites him to join her, and the two glance up at the Sakura.
Kanao says that the first user of Flower Breathing planted the tree. The tree’s name is “Victory” and Kanao wants to inform it that the Slayers succeeded. Tanjiro admires her kindness.
She tells Tanjiro that she still has some vision left in her eyes. Kanao unleashes a monstrous attack during the final battle that permanently blinds her, but it seems some vision still remains.
Kanao then tells Tanjiro that Sanemi, the Wind Hashira, arrived earlier in the day. He gives Kanao the Serpent Hashira’s sidekick, Kaburamaru. She says the snake is very intelligent.
Unfortunately, Iguro does not survive the final battle against Muzan. It is implied that off screen, Sanemi picks up Iguro’s snake in order to save it. He holds on to the snake until the battle dies down, then he gives it to Kanao.
So that’s the answer. Iguro does not directly give Kanao his pet snake. Sanemi, the Wind Hashira, picks up the snake after Iguro falls in battle and gives it to Kanao at a later time.