From the Super Mario Wiki
 Yoshi series
 Super Mario World 2: Yoshi's Island / Yoshi's Island: Super Mario Advance 3
Their first appearance is in Super Mario World 2: Yoshi's Island, where they act as minor recurring enemies throughout the game, and can have either white or yellow petals. Crazee Dayzees are essentially the same as Shy Guys in terms of game play, with the only difference between them is that if eaten and spat out, they will live unless they hit another enemy.
 Yoshi's Island DS
Crazee Dayzees appear again in the sequel Yoshi's Island DS where they once again act as enemies and are exactly the same as they were in the first game. They are found in many levels throughout the game, including Ba-dum BUM!, Hit the M Blocks!, Mario's Fleet Feet, Baby Mario and Baby Peach: Dynamic Duo and Donuts and Eggs.
 Paper Mario series
 Paper Mario
Crazee Dayzees make their first appearance outside of the Yoshi series in Paper Mario, where they appear as enemies in Flower Fields. They attack Mario on sight, and often fight alongside Bzzaps! and Ruff Puffs. A rare sub-species known as Amazy Dayzee appears in the game as well.
 Paper Mario: The Thousand Year Door
Crazee Dayzees, along with Amazy Dayzees, make a return appearance in Paper Mario: The Thousand-Year Door. In the game, they can be found along the Twilight Trail near Twilight Town, and later on Amazy Dayzees appear in the lower levels of the Pit of 100 Trials in Rogueport.
In the game, a green petaled Crazee Dayzee known as Hayzee appears as an ally of Luigi who joined him on his adventure to assemble the Marvelous Compass. Hayzee is also from a town of Crazee Dayzees known as Jazzafrazz Town, and, because of this, the game marks the first time that a Crazee Dayzee is given a personality and acts as an ally, and that a community of Crayzee Dayzees is mentioned.
 Super Paper Mario
Crazee Dayzees return in the third installment of the Paper Mario series Super Paper Mario. This time around they can be found in some of the many dimensions that Mario visits throughout his journey, such as The Dotwood Tree in the Bitlands and the Land of the Cragnons.
Crazee Dayzees appear to be anthropomorphic pansy flowers. They have four purple or yellow petals circling their face. Their face always have a big smile and rosy cheeks. Their bodies are small compared to their heads, and their bodies are green. They have two small green arms, and two purple or blue feet. The legs often move rapidly when the Dayzee runs.
 Traits and Abilities
Unlike many enemies in the Mario series, Crazee Dayzees are rather timid. When in peril, they prefer to run away than face the danger. They have little physical strength, although they have enough power to push Baby Mario off Yoshi's back. However, they can sing powerful lullabies that put their enemies to sleep. In the Yoshi series, they dance along and sing, but the song does not affect Yoshi. Their only difference from Shy Guys in this series is that they are not defeated if swallowed and spat out, unless they hit another enemy.
 Leadership and Allegiance
Crazee Dazyees, unlike many enemies in the Mario series, do not appear to have an allegiance with any character or group. However, in the distant past, when Mario and Luigi were babies, they were allied with Kamek, who was then the leader of the Koopa Troop. At this point, they may not have developed their lullaby-singing skills, as their only battle technique was to dance along passively.
In the Paper Mario series, Crazee Dayzees appear to have no allegiance, although they may be allied with the Koopa Troop in Paper Mario. In said game, they appeared as foes in Flower Fields. It is possible that they are under the control of Huff N. Puff at this time, though it is unlikely, as Crazee Dayzees are plant creatures, a type of organism that the Ruff Puff leader seems to dislike. If anyone, they are likely under the control of Bowser.
In Paper Mario: The Thousand-Year Door, Crazee Dayzees appear on the Twilight Trail, only in the forest portion. They appear to have no allegiance here. Thus, it is unknown why they attack passerby. It is possible that they consider Mario and his partners a threat and fight them off. However, they attempt to begin a battle in the field by running towards the red plumber.
A similar oddity exists for the Crazee Dayzees in Super Paper Mario. Here, they appear in the Dotwood Tree. Again, they appear to have no allegiance, but once again attack on sight. It is unknown why they attack the player.
Crazee Dayzees rarely appear as allies in the series. Instead, they appear as simple enemies existing to attack the player. However, in Paper Mario: The Thousand-Year Door, Luigi explains that during his adventures in the Waffle Kingdom, he came upon a civilized town of Dayzees called Jazzafrazz Town. They live in peace, and their most important activity appears to be the Jazzafrazz Town Drama Slam, where Dayzees show off their singing and dancing skills by putting on plays. The winner of this event earns the Dramalama Plaque, which was, at least once, a piece of the Marvelous Compass. An example of these civilized Dayzees is Luigi's friend Hayzee.
 Paper Mario series Stats and Tattle Information
 Notable Crazee Dayzees
 Names in Other Languages