Quicksand is a harzard that appears in certain Mario games. They are usually found in the desert and they are usually darker than the normal, safer sand. There is two types of quicksands: the ones that slowly pull Mario in allowing him time to jump out and the ones that instantly drag Mario under causing him to lose a life.
Appearances
Super Mario Bros. 3
Quicksand mainly appears in World 2 of this game. Mario can jump rapidly to get to avoid getting pulled under.
Super Mario 64/Super Mario 64 DS
Quicksand only appears in Shifting Sand Land for both of these games. Quicksand is a much darker color and as soon a character steps onto it, they get pulled under instantly losing a life.
Mario Kart series
Quicksand usually appears in desert-related levels of the Mario Kart games. Quicksand usually drastically slows down a character rather than pull them in. Heavy characters should always avoid this since they have poor acceleration.
Super Princess Peach
Quicksand appears in Wavy Beach of Super Princess Peach. Unlike other games, falling to the bottom of a quicksand pit doesn't instantly kill you instead, it just takes you to hidden niches that contain hidden secrets such as coins, Toad boxes, and more. You can easily jump out by rapidly mashing the jump button. Quicksand in the latter levels can also be pink. Certain pits actually have a bottom but it doesn't instantly kill you and is very shallow.
New Super Mario Bros. series
Quicksand always appear in the desert level of this game series. Like from Super Mario Bros. 3, Mario can jump rapidly to avoid losing a life. In some situations, sinking under the quicksand leads to secret paths and secret exits.
Super Mario Galaxy
Quicksand appears in Dusty Dune Galaxy and Sand Spiral Galaxy and instantly costs Mario or Luigi a life should they fall into it.
Paper Mario: Sticker Star
Quicksand appears in World 2 of this game mainly in the levels Drybake Desert and Sandshifter Ruins. Mario can jump over and over again to escape but he must be extremly careful. Sinking into the quicksand instanly earns him a Game Over.
Mario Golf: Toadstool Tour
Quicksand appears as an out-of-bounds area in this game. Quicksand is only seen in the course Shifting Sands as a darker orange color.