Goop

Graffiti, also known as Goop, is the thick, slimy residue Mario has to clean in Super Mario Sunshine with the help of the cleansing F.L.U.D.D.. There are many types of Goop and a few are helpful, while most are damaging and can make Mario slip. Many types can sink islanders, trees, or other structures underground. Most of the Graffiti is made by Bowser Jr. (under the guise of Shadow Mario) and his Magic Paintbrush.

Color Portal
Rainbow "M" logos used to transport Mario or Bowser Jr. to other parts of Isle Delfino and only found in Delfino Plaza. The first was painted by Shadow Mario to escape Mario after he foiled his first attempt to kidnap Peach at Delfino Plaza. This one was painted on the Grand Pianta Statue, and led to Bianco Hills. Two more teleporters behind the Blue Coin Shop, and on the Lighthouse (these are found only after the buildings have been saved from their Piranha Plant in the Generators. All Mario has to do is squirt water on them to activate them, then go through. The goop that makes up the teleporters is also found inside two red pipes; One on top of the building located near the Grand Pianta Statue (where it will be plugged up by a pineapple at the beginning of the game), and one on top of the Shine Gate. Pinna Park and Noki Bay are the only stages that don't use Color Portals. It is a rainbow color, shaped like an M, and turns into a window to the stage it leads to when approached. When Mario uses one of the three Color Portals, he seems to fragment into particles before entering, but for all modes of level transportation here, he's reassembled again at the stage start. Also, it appears in the pipes that lead to Sirena Beach and Pianta Village.

Forcefield
Undulating Forcefields used to hide items and clog Warp Pipes thus preventing Mario from entering and giving him one point of damage on contact. These forcefields can only be dissolved away by Yoshi Juice spit from a Yoshi. It has a zigzag-shaped pattern and undulates when Mario approaches. There are only six locations of the forcefields:
 * 1) On a small island off the coast of the fruit bazaar located in Delfino Plaza
 * 2) Behind the police station's tower
 * 3) On a high tower near the cannon to Pinna Park
 * 4) Covering a cage containing a Shine Sprite in Ricco Harbor
 * 5) Covering a Dune Bud in Gelato Beach
 * 6) On a flat mushroom under Pianta Village

Pink, White and Brown Graffiti
Tar-like Goop used to slicken the ground and make Mario slip and slide. If stood on for too long, Mario takes one point of damage each three to four seconds depending on the type. It also dirties and sticks to his clothes, which can removed by Spin Jumping or swimming in clean water. They are found almost everywhere and are the most common Goop. Some enemies release it while others are just infused with it. It is found in many colors and easily confusable with the Lava Goop and Electrogoop. Goop Generators are commonly paired with this Goop.

Electro Graffiti
Electric infused Goop that gives Mario one point of damage and stuns him for about 3 seconds. It is only released by the Phantamanta and its silhouettes in Hotel Delfino. The Goop was sealing the hotel underground and, because of their shoes which have very thick soles, it doesn't hurt Piantas (or Nokis for some reason). Phantamanta appears yet again while Mario is gone, and in Episode 6 Mario had to clean up all the Goop before the timer ran out. It looks like a mixture of green and yellow and has electricity surging from it. On a side note, when Mario touches this type of Goop, it will momentarily change his colors to the negative image.

Lava Graffiti
Lava-like Goop that gives Mario one point of damage on contact and send him flying up, just like regular Lava. It is only found in Pianta Village and produced by Chain Chomplets. Smolderin' Stus and Coo Coos also drop it in later Episodes. It also somehow reappears again in Episode 3 in which Mario had to successfully save the Mayor from the fiery inferno. The Goop is also seen in Episode 6 where Mario had to save the Piantas stuck under puddles of it. If Mario is caught in the center of a huge puddle of the Goop, he will most likely lose a life or be heavily damaged because of the chain of damage from flying up and landing again in it. It is orange-red and releases a spurt of flame every now and then. Shadow Mario creates it in Shadow Mario Runs Wild as he runs.

Poisonous Water
Goop polluted water that damages Mario by one point about every two seconds he's in it. Strangely, it only affects him while on the surface of the water and doesn't hurt him when under the water (though if he stays underwater too long, he will drown). There are three locations of Poison Water; In Episode 6 of Bianco Hills, Episodes 1-5 of Ricco Harbor, and the first 4 Episodes in Noki Bay. The colors vary on the the stage in which it is in. Bianco Hills had brownish sick-like colored Poison Water, Ricco Harbor had black oil like Poison Water, and Noki Bay had purple transparent Poison Water.

Wall Graffiti
The main type of Goop that Bowser Jr./Shadow Mario uses. It can be used to create other types of Goop. For example, Shadow Mario is seen painting Color Portals with the Magic Paintbrush, which is tipped with Graffiti. There also is a "raw" form by which Shadow Mario uses to paint his infamous signature. When Graffiti is sprayed and cleaned, they can release a Gold Coin or a Blue Coin. There is also a similar Shine Sprite painting that can be found in a few places and release a Shine Sprite when sprayed on long enough. It is invisible at default so it is hard to find. Another type of Graffiti is painted in shapes and only appear in pairs. When one symbol is cleaned, a Blue Coin appears next to another matching symbol and vice-versa. The shapes consist of a triangle, a X, and a circle. It is colored red and is unlimited in supply when on the Magic Paintbrush.

Tub Slime
Hot, poisonous Goop that Bowser and his son, Bowser Jr., bathe in during the final battle. It has the same properties as Lava Goop but unlike the other Goop, it cannot be removed or cleaned. Bowser sometimes Ground Pounds the tub to splash the Slime on Mario and damage him. There seems to be a unlimited amount of Tub Slime in the tub because when Bowser tilts the tub, most of it falls out but is immediately replenished. Tub Slime is only found in Bowser's bathtub at the top of Corona Mountain. It has a light green color with a jelly-like texture and is searing hot.When Mario tips Bowser's tub up all of the Tub Slime falls out of it into Corona Mountain.

Other Appearances
Throughout Super Mario Sunshine, there are also Goop enemies in the game like the Piranha Plant in the Generator and Swoopin' Stus.

Goop also appears in Mario Power Tennis as an obstacle on the Delfino Plaza court. It can cause players to slip and slide around. The player must also clear away Goop in a tic-tac-toe-like minigame called Tic-Tac-Glow.

Goop appears in several Mario Party games.

Trivia

 * If a Sewer cover is covered in Goop, Mario cannot go through it, even if he ground pounds on it. He must spray it first.
 * Graffiti (different to Goop) was seen in The Adventures of Super Mario Bros. 3 in the episode "7 Continents for 7 Koopas", where Bully Koopa used a can of spray to paint graffiti on the Great Wall of China. Also, in Mario Party 8, there is a mini-game called "Speedy Graffiti", which obviously involved graffiti.