Unfezant, as a Pidove is Mio's fourth Pokémon she caught during the Festival. She was confirmed female.
As a Pidove, she was very energetic when hearing festival music and as a result, she appears from her PokeBall with hearts surrounding it, she evolved into Tranquill in A Sky Battle Of Tranquility during a battle against Ash's Talonflame and learned Aerial Ace in the process, in a fierce battle, the match was a tie due to both Talonflame and Tranquill knocking each other out.
As a Tranquill, she maintained her personality but she is very kind to the Light Music Club, since it evolved, she is very fast and very curious upon Mio's singing, she loves being taken care of by Bonnie. When she was a Pidove, she used her beak to pull Bonnie away and brought over to Clemont when she proposed to Mio to be her wife which embarraseed her. She is often a straight-man despite being female which occurred in Dancing With Graceful Fairies.
After a fierce battle against wild Tropius, she evolved into Unfezant, and learned Sky Attack in the process. She is easily embarrassed just like her Trainer, however, she will often risk her life for Mio. She can be alert when Mio has a problem and she'd often ask what the problem is.
As an Unfezant, Like Pidove and Tranquill, she kept her personality, kind and caring to the other Pokémon Mio has on her team, and will try and shield Mio when threatened.
In "What's In a Nickname?", she was officially nicknamed Twitter by Mio, and even nicknamed the other Pokemon she has.
Unfezant's known moves are: Sky Attack, Night Slash, Heat Wave, Roost and her ability is Super Luck.