Musha, at times, is shown to be very gluttonous for his favorite food, dreams, even flying away from his Trainer when he senses a tasty one in the vicinity.
Musha eating Black's dream for the first time
Black first met Musha when he was only five years old. During a battle with a wild Rufflet, Black's dreams caused him to begin daydreaming and made him completely unable to focus. This attracted Musha, who then bit down on Black's head, much to the horror of Cheren. This allowed Black to figure out that the Rufflet was angry because Bianca had stepped on its food, which led to it attacking her.
The next day, Black attempted to capture the Rufflet and make it his own Pokémon. Although it seemed like Black was at a disadvantage because he didn't have another Pokémon to battle with, Black reveals that he asked Musha to help him with the reward of letting it eat his dreams. Together, Black and Musha battle the Rufflet and eventually defeat and capture it, where it was named Brav. Afterward, Black allows Musha to join his team and gives it the nickname Musha for its evolved form, Musharna.
Musha was first seen in Choices with Black and Brav. When Black went to rescue a runaway Tepig, he used Musha to scout out a wild attacking Sewaddle, allowing him to defeat it. Musha, along with Tep, and Brav, were used against Hiker Andy, where they managed to defeat his three Pokémon in a Triple Battle. Musha was used to help Black find out a way to stop the fire that Andy's Cottonee had accidentally started.
In Listening to Pokémon, Musha flies away from Black after sensing a powerful dream. With the help of Professor Fennel, Black and White find Musha in the hands of some Team Plasma Grunts. When Black tries to figure out a plan to defeat them, his brain overloads from trying to think of something that doesn't involve the Pokémon League. Musha becomes attracted to this overflow of dreams and flies from the grasp of the Grunts and goes back to Black. With the help of Musha, Black manages to defeat the Grunts and drive them out.
Musha is later used in Black's Gym battle against the Nacrene City Gym Leader, Lenora. He fought her Stoutland briefly before being sent back into his Poké Ball by its Roar. Later, after Brav was knocked out and the two Trainers only had one Pokémon left, Musha was sent out to battle Stoutland again, this time defeating it with Zen Headbutt.
Sometime later, Musha is used in Black's Gym battle against the Gym Leader of Driftveil City, Clay. Musha battles Clay's Palpitoad and is trapped by its long tongue. Eventually Musha manages to knock out Palpitoad with a Zen Headbutt but faints in the process. In Black's Gym battle against Brycen, Musha was sent out to battle Brycen's Vanillish, only to be quickly defeated.
After battling N, Musha was revealed to have only followed Black's orders because he considers Black's dreams to be tasty and kept him fed. After the taste of Black's dreams changed over the course of his adventure, Musha decides to leave Black. After Black defeated Cheren at the Pokémon League, Musha returns to Black, now evolved into a Musharna. It was later revealed in a flashback that Musha wanted to become stronger, and so Caitlin, who saw Musha wandering around, decided to use a Moon Stone on it to evolve.
| Using Zen Headbutt as a Munna
| An × shows that the move cannot be legitimately learned by this Pokémon in the games.
| A † shows that the move was used recently, unless all moves fit this case or there are fewer than five known moves.
||From ムシャーナ Musharna, Munna's evolved form
||Same as the Japanese name
||From Somnivora, Musharna
||From 몽얌나 Mong-yamna, Musharna
||From 夢夢蝕 Mèngmèngshí, Musharna
||From 夢夢蝕 Muhngmuhngsihk, Musharna
For more information on this Pokémon's species, see Munna and Musharna.