Warp Block

The Warp Block is a block in the Mario Party series that, when used, will transport a character who hits it to another character's space. In turn, the player that they travel to will then be transported to their initial spot. It appears in Mario Party, Mario Party 2, Mario Party 3, and Mario Party Superstars.

Mario Party series
In Mario Party, it can be bought at the Mushroom Shop, and when turned on, it will appear in a random space to be automatically used when the player stops on it.

In Mario Party 2 and Mario Party 3, the Warp Block can be purchased at the Item Shop on the board or obtained from the Item mini-game. It can be used anytime. It is also Yoshi's favorite item.

In Mario Party 4, the Warp Block is replaced by the Warp Pipe, and has been its successor ever since, though Yoshi's bio in the Mario Party 4 instruction booklet mentions them, possibly referring to Warp Spaces.

Mario Party DS has an item analog to the Warp Block, called the Warp Dice Block. It doesn't switch the character who used it with another character. Instead, it lets the user warp to a random space.

In Mario Party: Star Rush, Mario Party: The Top 100, and Super Mario Party, the Warp Box from Super Mario 3D Land takes on the Warp Block's role, teleporting the player to a chosen rival's space when used, but does not swap places with the rival, and the Warp Pipe item is absent.

After a long absence, the Warp Block returns in Mario Party Superstars with a different appearance: the rainbow color is now shifting and the question marks on all sides are replaced by two circular arrows that appear on one side, instead of all sides. It reprises its function from Mario Party, Mario Party 2, and Mario Party 3.

Mario & Luigi: Partners in Time
Warp Blocks appear in Mario & Luigi: Partners in Time with a different design than in the Mario Party series. It is blue and has a picture of a Warp Pipe on one side. When Mario and Luigi's (or Baby Mario and Baby Luigi's) younger/older selves are too far away, if one pair hits a Warp Block, a Warp Pipe will appear and shoot their companions out.