Poisoned Water (also called Poison Water, Purple Water, Toxic Water, Poison Swamp, Poison Bog, Poison, or simply Muck) is a dangerous goopy type of water commonly found in Jungles and Forests, it serves as a major hazard for Mario and friends to cross, touching Poisoned Water is like touching Lava, it is an instant-death in almost all of it's appearances, not even a Starman can protect the heroes from this deadly obstacle however, in some games, it merely does damage so this could mean that some Poisoned Waters have different levels of toxicity that differ from game to game.
Super Mario series
Super Mario 64/Super Mario 64 DS
Regular Poisoned Water doesn't appear in Super Mario 64 and Super Mario 64 DS but a similar substance called Toxic Gas does, it can be found in Goomboss Battle and Hazy Maze Cave and deals damage when walked in.
Super Mario Sunshine
Poisoned Water is first seen in Super Mario Sunshine exclusively appearing in the Lily Pad Ride course. Poisoned Water looks identical to normal water but if Mario takes one step in the water, he is killed instantly. Mario must ride a Lily Pad across the Poisoned Water river and collect 8 Red Coins on his way to the end, due to the Poison, the Lily Pad is slowly withering so Mario must be quick or else he's going down with the Lily Pad. The Poisoned Water appears to go through a drain which descends into the abyss in the form of a waterfall.
New Super Mario Bros.
Poisoned Water is seen again in New Super Mario Bros., in this game, Poisoned Water is now Purple (which would go onto become it's primary color for future appearances), it looks identical to normal water but is far more dangerous and will kill Mario (or Luigi) upon contact. Poisoned Water is commonly seen in World 4, in two levels the plumbers need to use Dorrie to cross the toxic lakes and in others, they need to rely heavily on platforming skills to avoid falling into the muck. Poisoned Water is also seen around the map of World 4 and later reappears in World 6-3 as a semi-primary hazard in the Caverns of the level.
Super Mario Galaxy
Poisoned Water returns in Super Mario Galaxy retaining a similar role to previous games but can come in either Purple or Green colors and it also appears more gloopy. Poisoned Water is first seen in the Bubble Breeze Galaxy where it makes up the entire ocean of the Galaxy and is the primary hazard for the Galaxy, of course, there are also Mines and other hazards which can in turn knock you into the Poisoned Water. Poisoned Water later appears in the Toy Time Galaxy specifically in the Luigi's Purple Coins mission where it makes up the dark green parts of the 8-Bit Luigi Planet. In this game, Poisoned Water is an instant kill hazard and is more similar to Quicksand where if you stumble in it, you slowly sink in with no chance of escape (unlike Lava in which you bounce out of with one less health). A similar hazard to Poisoned Water called Dark Matter also appears in this game, while it appears to be gloopy, Dark Matter is actually made of plasma and will disintegrate those who touch it.
New Super Mario Bros. Wii
Poisoned Water returns in New Super Mario Bros. Wii, in this game, it now resembles Lava more than regular water making it more clear that touching it is hazardous. Poisoned Water is commonly seen in World 5 as a common hazard of this world, Mega Wigglers can crawl through Poisoned Water without an issue, Mario can use the help Mega Wigglers to cross the dangerous chasms, in World 5-4, Poisoned Water is a primary hazard and must be avoided at all costs as you sail the waters.
Super Mario Galaxy 2
Poisoned Water is seen again in Super Mario Galaxy 2 appearing in the secret planet of the Cloudy Court Galaxy, the Boo Moon Galaxy, and the Mario-Squared Galaxy making up the dark green parts of the 8-Bit Luigi Planet. Poisoned Water returns to it's gloopy appearance in this game and can come in either Purple or Green Colors. Just as before, sinking into Poisoned Water is like sinking in Quicksand as it slowly sinks you under killing you instantly. Dark Matter also returns in this game.
Super Mario 3D Land
Poisoned Water returns in Super Mario 3D Land, in this game, it is much less common only appearing in the sewer tunnels of World 2-2 and Special 6-3. Poisoned Water is once again Purple in this game and is once again an instant-death hazard. Poisoned Water sometimes takes up large parts of the area and Mario/Luigi must use the Flip Panels to form bridges cross the chasms.
New Super Mario Bros. 2
Poisoned Water is back in New Super Mario Bros. 2 appearing in several levels of World 3, it retains a very similar appearance to New Super Mario Bros. Wii and once again is an instant-death hazard. In World 3-4, Poisoned Water is shown to rise and drain in a tidal manner. Mario/Luigi must keep an eye on the purple parts of the platforms to tell how high the Poisoned Water goes, there are some platforms that sink upon being stood on so the plumbers should try not to linger idly on these platforms for too long. In World Flower-2, there is also a Porcupuffer which swims in the Poisoned Waters as it attacks.
New Super Mario Bros. U/New Super Luigi U/New Super Mario Bros. U Deluxe
Poisoned Water also appears in New Super Mario Bros. U as well as New Super Luigi U and New Super Mario Bros. U Deluxe retaining it's appearance and function from the previous games. In this game, it is commonly seen in the Soda Jungle and is also seen around the world map of said world. Just as before, Mega Wigglers can walk through the Poisoned Water without an issue which becomes of even more use here as they are used to cross the poisonous seas in Wiggler Stampede. Some levels like Dancing Blocks, Poison Swamp also have platforms which emerge and descend from the Poisoned Water periodically. Wiggler Floodlands also has rising Poisoned Water which floods the level and must be avoided. Poisoned Water is also seen in levels of Rock-Candy Mines and Superstar Road. Due to it's drink-like appearance, it is possible that Soda Jungle is named after the Poisoned Water.
Super Mario 3D World/Super Mario 3D World + Bowser's Fury
Poisoned Water returns in Super Mario 3D World and Super Mario 3D World + Bowser's Fury appearing in dark forest-themed levels such as Piranha Creeper Creek, Deep Jungle Drift, and various other haunted-themed levels. Just as before, it is an instant-death hazard and must be avoided at all costs. Poisoned Water, can be avoided with the use of platforming.
Super Mario Run
Poisoned Water returns in Super Mario Run retaining it's role from the previous 2D Mario games, it is a one-hit-kill hazard once again so avoid it at all costs, Poisoned Water is commonly seen in Jungle-themed levels as usual and commonly must be hopped across to Spike Bar Jungle also has Poison Podoboos which hop out of the Poisoned Water periodically similar to the Podoboos with Lava.
Super Mario Odyssey
Poisoned Water is seen yet again in Super Mario Odyssey. In this game, it makes up the oceans of the Lost Kingdom. Pools of Poisoned Water can also be found on the main land, Mario must use platforming skills to make it across the Poisoned Water, sometimes this requires the use of a Tropical Wiggler. Unlike Lava (which has been downgraded to a one-point damage obstacle again), Poisoned Water is an instant-death hazard once again.
Super Mario Maker 2
Poisoned Water appears again in Super Mario Maker 2 as a placeable obstacle in the Forest-Night theme replacing the Water in that theme, it serves the same role it did in the 2D Platformers being an instant-kill hazard like lava and can be set to rise or have a tidal effect.
Paper Mario series
Paper Mario: Sticker Star
Poisoned Water appears in World 3 of Paper Mario: Sticker Star. In this game, it is caused by Gooper Blooper after the Purple Royal Sticker landed on his head. The Poison leaked through the ocean and drenched the entire forest leaving many poisonous puddles and clouds and flodding the pits with Gloopy Poisoned Water and darkening the Forest. Snifits and Poison Bloopers are commonly seen around the Poisoned Water. If Mario walks in the Poisoned Water, he takes 3 HP of damage. Loop Loop River also has a flowing river of Poisoned Water which causes you (as well as any items that fall in) to travel with the flowing waters so Mario needs to make use of the Lily Pads to traverse the Gloopy Waters. There is also a Poisonous Hot Spring in Tree Branch Trail which is necessary for a Wiggler Diary Entry. After bringing back Wiggler's Segments to Wiggler, he will take Mario and Kersti to the Island off Whitecap Beach to find the source of the Poison to save the forest so Wiggler can snack on his favorite diet of leaves and plants again. After Gooper Blooper's defeat, and the Royal Sticker is claimed, the Forest lights up and all the Poison disappears leaving several small pits in it's place, also, the Poison Bloopers all disappear.
Paper Mario: Color Splash
Poisoned Water returns in Paper Mario: Color Splash with a similar role to the previous game however unlike before, the Poisoned Water is now the subject of a single level rather than an entire world. The Poisoned Water can be found in Plum Park. Falling in it will cause Mario to lose some HP, Poison Bloopers can also be seen around the Poisoned Water just as before. This time, the cause of the Poison is none other than Petea Piranha (a mutant Piranha Plant similar to Petey Piranha), he is seen clogging the centeral Tea Pot and engages Mario and Huey in battle once they reach him, after his defeat and the Tea Pot has been obtained, Plum Park's poison is reversed and is changed into a lustrously harmless blue water, the sky goes from a gloomy purple to a peaceful blue, and the park becomes more active as more visitors arrive and the closed Flowers are now opened and can be used as platforms. Also, the Poison Bloopers are replaced with regular Bloopers.
Mario Party series
Mario Party 9
Poisoned Water appears in Mario Party 9 in the minigame Bomb Barge. Players are on a raft traveling across a lake of Poisoned Water and battle it out as Bob-ombs rain down on the raft, those that are hit by the Bob-ombs when they explode are knock back a few feet, anyone who falls into the Poisoned Water is immediately eliminated from the game, players can kick the Bob-ombs to their rivals to increase the chances of them falling in. Whoever is the last player standing is the winner.
Mario Party 10
Poisoned Water appears in the Mario Party 10 minigame Platform Push. In this minigame, players fight to in a battle royale push each other off the grassy platform and into the Poisoned Water below. Whoever is knocked into the Poisoned Water is eliminated and the winner is the last player standing. Players can jump on and punch each other to knock their rivals into the Poisoned Water or to defend themselves from incoming attacks from rivals.
Mario Party: Star Rush
Poisoned Water is seen again in Mario Party: Star Rush in the minigame Bridgesaw Puzzle. In the minigame, Poisoned Water is seen below the two ledges and players need to construct bridges from the shaped blocks to cross the Poisoned River. Whoever builds their bridge fastest and most efficiently earns more points. After the minigame is over, the players exit the forest and are greeted by a clean blue lake. Unlike previous games in the Mario Party series, players cannot fall into the Poisoned Water in this game.
- Originally, Poisoned Water appeared to look similar to the non-hazardous water, it was later changed to look more like Lava in more recent games most likely to imply that it's hazardous and should be avoided.