If the wheel on Bowsers space hits an event called "Bowser's Multiplying Toads", a Toad clone would appear, if you land on the fake Toad, it would reveal that he is actually Koopa kid as he gives you a Ztar, but it doesn't take away your star, AND has no effect on the Star count.
Ztar appears in the background on the boards Thwomp's Mega Board Mayhem and Thwomp's Mini Board Madness as extras. It flies in a circle and is not important. Later in the game, Ztar challenges the player to a game of beach volleyball.
However, the black star's effect was first introduced until in this appearance, where it mainly appears in the Card Party. Sometimes when a Star Card is reached this star will appear, referred to as a Ztar Star. It makes the player lose a star, If the Ztar stays for a while in the card, It may get brighter, and suddenly it reveals a Star. Or sometimes it shows a small "Yellow Glow" but it turns black again. Ztar may also appear from a Star, the star when it stays in the card, it starts growing bigger, if it grows too much, it starts shaking, and it explodes, Revealing a Ztar Star. Bowser may also award it to a player as a "Star Present", It first resembles a glowing, Yellow Star, But it starts shaking, and it explodes, Revealing a Ztar (As said before, this may also happen with normal Star cards). He can also give it away on a Bowser Space.
Ztar appears as the Shadow Star. Here, it once again counts as a negative star. It is given to the player by Bowser on Bowser's Battle Yacht in Castaway Bay. He also gives it to the player on Clockwork Castle where it even has a space known as the Shadow Star Space. Here, the 20-coin Shadow Star is also introduced, given to the player by Bowser if they have no Stars. It makes the player lose 20 coins.
A Blooper in Grand Canal may also give the player a Dark Star, as it is called in this appearance. At a ? Space at the top of the board, it is put in a chest and recycled with other chests with various prizes. If the chest with the Dark Star is chosen, the player will lose one star.
Mario Party 9
Mario Party: Island Tour
As with Mario Party 9, Ztars do not appear in Mario Party: Island Tour. However, Mini Ztars return. They are found exclusively on the Star-Crossed Skyway board and have the same function as before, deducting Mini Stars when collected.
Mario Party 10
Ztars themselves do not appear, though Mini Ztars do, and function as they do in Mario Party 9 and Mario Party: Island Tour.
In the mini-game Cosmic Coaster, if one of the teams get the Star in the goal first and the other team doesn't get it but they get close to it, the losing team can see the Star in the goal as a Ztar falling to the ground. Also, before reaching the goal, the star looks like a Ztar.