Mesprit is a greyish-blue, fairy-like Pokémon. Mesprit has two long tails encrusted with two red gems. Mesprit has a hot pink face and a flat helmet or a head with four drooping pig tails or appendages, yellow eyes and another red gem onto its forehead. While it is genderless like all other Legendaries, it has a feminine appearance.
In Pokémon Mystery Dungeon, despite being depicted as a calm and peaceful Pokémon, she seems a little violent and was so enraged, she wouldn't listen to the hero and their partner, and attacked them fiercely. After defeat, she feels exhausted, and gasping for air slowly and still not believing to the hero's partner but she said who is responsible to take its friend's Time Gear, it is revealed that Grovyle is doing this. So he arrive and beg Mesprit to take the Time Gear but she won't let him to take it, Grovyle knock Mesprit down to the ground and dive underwater and take the Time Gear quickly while Mesprit apologizing to the hero and the partner for doubting them. But Mesprit tells that it is too late to save its Time Gear, the dungeon is about to stop in time, so Mesprit ask the hero and partner to escape before they will stuck in time, so she flew away from the dungeon and the hero and partner fulfilling escapes the dungeon.
After the player defeats the Champion, the player can go east of Floccesy Town and head towards Route 20, and surf to the Cave of Being. Once inside, the player will see Professor Juniper, and after she finishes speaking, Mesprit, Azelf, and Uxie will all appear. They will soon fly off. When the player reaches Route 8, they can choose to enter Celestial Tower. Once they reach the top, the player can approach the stairs to ring the bell, but a text box will read that a mysterious presence can be felt, and the player is given the option to search around. If they choose "Yes", then Mesprit will appear.
Mesprit appeared in DP001. In the episode, shortly after Dawn and Piplup got to Lake Verity, a strange whirlwind started. A strange figure appeared out of the lake, which was Mesprit, it slowly moves around a bit, when it sees the two, it gets scared and disappears. The same happens to Ash and Brock. Mesprit also appeared in another episode when Dialga and Palkia were out of control. It teamed up with Dawn to save them while Uxie teamed up with Brock and Azelf teamed up with Ash.
Just like the other members of the lake trio, the second half of Mesprit's name sounds like something magical. In Mesprit's case, the second half of its name comes from the French word "Esprit" which means "Spirit".
It is possible that Cyrus has seen, and touched, Mesprit. This is theorized because Cyrus seems to have no emotion.
Mesprit is the only member of the Lake Trio that is a roaming Pokémon.
Although genderless in the main games, Mesprit is referred to as a female in the Pokémon Mystery Dungeon games, making it the only Lake Guardian to have a feminine appearance.
Mesprit and Kirlia have the same species, the Emotion Pokémon.