Boo
Description History of the Series: In Mario Parties 1-4, Boo was used to steal coins or stars from other characters. In Mario Party 5, he became a playable character and ChainChomp/Pink Boo was replaced for stealing coins/stars.
First Mario Party Appearance: Mario Party
Last Mario Party Appearance: Mario Party DS
First Mario Party Appearance as a Playable Character: Mario Party 5
Last Mario Party Appearance as a Playable Character: Mario Party 8
Facts about Boo: In the olden times, Boo used to scare people, but now they conquered their fear over humans. Boo has also appeared in Mario Sports games and other Mario spin-offs.
Diddy Kong
Description History of the Series: Diddy Kong does not have that much history in the Series, for only he appeared in Mario Party DS as a Story character so far.
First Mario Party Appearance: Mario Party DS
Last Mario Party Appearance: Mario Party DS
First Mario Party Appearance as a Playable Character: N/A
Last Mario Party Appearance as a Playable Character: N/A
Facts about Diddy Kong: Diddy Kong is Donkey Kong's sidekick, and helped out DK whenever in need. Diddy Kong has been appearing in many Mario games since Mario Golf: Toadstool Tour on the Nintendo GameCube.
Mario
Description History of the Series: Mario has been in every Mario Party to date. Obviously, Mario has been partying since 1998. He has been playable in every Mario Party as well. And he just wants to have fun with his friends.
First Mario Party Appearance: Mario Party
Last Mario Party Appearance: Mario Party DS
First Mario Party Appearance as a Playable Character: Mario Party
Last Mario Party Appearance as a Playable Character: Mario Party DS
Facts about Mario: Mario is Nintendo's top mascot. Mario has a lot of his own games and was once called "Jumpman" in Donkey Kong Arcade in 1981.
Luigi
Description History of the Series: Luigi has been in every Mario Party as well. Luigi is just here to make sure his brother is having fun partying.
First Mario Party Appearance: Mario Party
Last Mario Party Appearance: Mario Party DS
First Mario Party Appearance as a Playable Character: Mario Party
Last Mario Party Appearance as a Playable Character: Mario Party DS
Facts about Luigi: Luigi is Mario's younger brother. He has been having fun with Mario in all the games like racing and sports. Luigi also starred in one of the first Nintendo GameCube games, Luigi's Mansion.
Dry Bones
Description History of the Series: Dry Bones has appeared in three Mario Party games so far. In Mario Party DS, he appeared as a boss after you win DK's Stone Statue in Story Mode.
First Mario Party Appearance: Mario Party 7
Last Mario Party Appearance: Mario Party DS
First Mario Party Appearance as a Playable Character: Mario Party 7
Last Mario Party Appearance as a Playable Character: Mario Party 8
Facts about Dry Bones: In the olden times, Dry Bones has appeared in Mario games as an enemy. He even appeared in Mario baseball games to play ball.
Here's mine. Look good to you guys? Anything I might need to fix?