From the Super Mario Wiki
The Blooper-Go-Round is a space that first appears in Mario Party 10, only on the board Mushroom Park. It is a four-saucer carousel in the shape of a Blooper. If the player passes one, they will be given an opportunity to receive zero, zero, five, or ten Mini Stars in Mario Party mode, or zero, zero, two, or four hearts in Bowser Party mode, as determined by a roulette. Only one of this space appears on the entire board, that of which is present just before the Homestretch.