|"Don't feel so guilty! Ha ha ha!"|
|―Boo, Mario Party|
Boo is a playable and non-playable character in the Mario Party series.
Boo is a ghost-like character in Mario Party series. He is a pale-white ghost with fangs.
Boos made several appearances in this Mario Party. Boos appeared in boards apart from Peach's Birthday Cake. On Boos help players steal coins from other players for free or steal a Star for 50 Coins. If a player does neither of them, Boo will disappear and responds "Don't feel so guilty! Ha ha ha!". Boo also appears in the board's endings. Boo also makes appearance in the mini-games Running of the Bulb, Crazy Cutter, Ghost Guess and a Big Boo appears in Pedal Power.
Boos also help players steal coins and stars from other players on boards. Boo makes a few appearances in some minigames.
Boos also steal coins and stars from other players and gives them to the player. He makes a few appearances in minigames.
There is a Boo who hosts Boo's Haunted Bash. After the player wins the board, Boo challenges the player in a minigame called Mystic Match 'Em. Boo and other hosts reward the player the Star after winning their minigame. On boards, a Boo controls the Item Shop, another owns the Mystery Train; but it only gives out rides to the Boneyard if a Red Boo is absent. Two side-games involves Boos requiring a Mini Mushroom, another Boo of them has the player pressing one of the keys of the Horn of Plenty to get one of three randomly chosen items, and the second Boo has the character on a piano; They have to press the correct key at the right time until the end of the side-game to get a certain amount of Coins.
Boo started as a playable character in Mario Party 5. Boo's nickname is "Nightmare Boo". In Super Duel Mode, he has a Sheer Sideswipe.
|Koopa Kid||Pure Evil|
Boo is playable character again in Mario Party 6. There is also an orb called Boo Away Orb, which protects the player from a Red Boo. Red Boos also appear in the minigame Boo'd Off the Stage and Boonanza!. Red Boos also appear two boards at night, Towering Treetop and Castaway Bay where they let players steal coins and stars from players. This game also marks the third appearance of Red Boos in the Mario Party series. The team names are the same as the previous game. When Boo allies with Toadette, their team is called "Terrifying Twosome".
Boo appears as a non-playable supporting character in Mario Party Advance. Boos appear in the Boo Cemetery where they are the main characters in the quest, True-Blue Boo. This is a mystery quest, in which their golden Boo statue has been stolen, and the player must find the Boo who stole it. There are four Boos and the player can find the thief who is disguising as a Boo with some hints. The fake Boo turns out to be Koopa Kid who flees the area and leaves the statue behind. The Boos then reward the player with the Gaddget, Predictotron.
Boo is a playable character in Mario Party 7. It marks Dry Bones' first playable appearance in the Mario Party series, Dry Bones is Boo's main partner throughout the game. Red Boos also appear in the game. Red Boos appear in a few minigames such as Ghost in the Hall. The Red Boos oddly scare Boo. Boo shares the same special orb with Dry Bones, the Magic Orb. It allows them to double their dice roll during the next two turns and they become invincible.
|Daisy||High Spirited Duo|
|Dry Bones||Scary Pair|
|Hammer Bros.||Bad Vibes|
Boos are non-playable characters in Mario Party 9. They appear in Boo's Horror Castle, Boos come out of portraits if the player's vehicle comes pass them. Boos move every three spaces after the player's move. Players can escape castles and the doors shut which the Boos cannot chase them. anymore. The Boo will chase up the player if the vehicle is close to them, thus the captain loses half of his/her Mini Stars and the Boo leaves them. Boos only appear in the minigame, King Boo's Puzzle Attack. When King Boo enrages, King Boo sends Boos that will distract the player and the player can shake it off with his/her Wii Remote.
Boo is a playable character in Mario Party: Island Tour. This is the first time Boo is playable on a handheld Mario Party game. Boo is the first character in the series to be removed as a playable character in a main installment of the series and then return in a later installment.