Toxic Forest is a course that appears in Mario Kart 9th. It is the first course of the Star Cup and is heavily inspired by world similar to Soda Jungle.
At the start you drive forwards over just a road and shortly after that make a right turn over a bridge, immediately followed by a jump on a mushroom with item boxes. You continue driving upwards and make an u-turn in anti-gravity while driving over some poisoned water streams with item boxes being carried along with the stream. You go downwards and enter a haunted forest. The background has changed into the paint-art style of The Starry Night. You have to dodge creepy trees. Halfway the forest are item boxes. You can take a shortcut with a mushroom by driving over a log in the water. As you leave the forest you go over a paraglide jump. You get a speed boost when flying through the Circling Boo Buddies and jump on the mushrooms so you won't exit the paraglide mode. You land again in the entrance of a cave with many turns. Inside of the cave are Bramballs that occasionally switch their feet. Halfway are item boxes. As you leave the cave you drive towards the finish.
Most of the out-of-boundary of the stage is purple poisoned water. The mushrooms are the same as the one in Mushroom Gorge only they all are purple. When you're in anti-gravity and pass the steams they come out of pipes that are against the walls. The trees are exactly like the ones in the backgrounds of Twisted Mansion and the haunted forest levels of NSMBU. The circling boo buddies almost all have different faces. The inside of the cave is filled with crystals on the side. The Bramballs are like they always are in the games.