Slowgo Candy is a red candy from Mario Party 8.
It has the combined effects of the Sluggish 'Shroom Orb and Poison Shroom items from the previous Mario Party games. When it used, you will get to hit a slow-moving dice block (hence the name) with 1-5 on it. It is usually more expensive than the Twice Candy, costing 10 or 15 coins. It has a picture of a green dice block on the wrapper with the number 5 on all sides.
The Slow Dice Block from Mario Party 9 and Mario Party 10 has a similar effect to the Slowgo Candy.