Fungi Forest

Fungi Forest is the fifth level of Donkey Kong 64, which is accessible after the player returns the Gloomy Galleon Boss Key to K. Lumsy's prison, and has collected 50 Golden Bananas. It is, as the name states, full of mushrooms. The stage centers around a giant Cuckoo Clock. The Cuckoo Clock has the ability to change day into night and vice-versa. Many areas are only accessible during certain times of the day. Enemies are also affected by time. They often become more hostile when the sun goes down. Dogadon is fought in a rematch by Chunky Kong here.

This level also introduces blue Kong Switches, though a blue one does appear in the lobby of Gloomy Galleon. They can only be activated once the Kongs get the Super Simian Slam potion from Cranky Kong.

Although this is the second level that Candy's Music Shop does not appear in (the first being Jungle Japes), her headphones can be found at various locations in this level.

Starting area
This area is notable for the giant clock where the Kongs can change between day and night, and vice-versa. The first 1, 2, 3, and 4 bananaport pads are located here. It has three tunnels leading to three different areas. The colors of the tunnels are indicated by three of the four bananaport pads in the area. In other words, the blue tunnel leads to the Mill Area with the blue #1 pad; the green leads to the garden with the #2 pad; and the purple leads to the giant mushroom with the #3. The well leading to Chunky's minecart bonus game is located here.

Mill area
This area contains several barns and mills that house several creepy enemies. Inside these mills are mechanical tasks the Kongs will have to face to get their Golden Bananas. These tasks include walking on dimly lit planks, turning on a conveyor belt, taking out Bats in the attic, and battling a giant spider with Tiny Kong only. Snide's H.Q. appears in this area, but is only accessible during the day. The 1 pad is located here. There is a section surrounded by dangerous plants which can only be accessed at night. It contains Donkey Kong's Kasplat and a shed containing a Bonus Barrel. Both Banana Fairies are in the area and are hidden in buildings only accessible at night.

Garden area
This area requires Tiny and Chunky to open with their shooters. It has a tomato patch with several Tomatoes surrounding an apple with a Worm in it, which can be moved by Chunky to the starting area for a Golden Banana. Tiny Kong can plant a seed from the treestump in the Big Tree Area in a hole which grows a giant living beanstalk. Funky's Store and a 2 pad can be found here.

Giant mushroom area
This area has a gigantic mushroom surrounded by water. Inside the fungus, the Kongs have to climb up the different floors of this mushroom to tackle bananas and bonus barrels. These floors also lead to terraces outside, which have many other tasks as well. Cranky's Lab, a 3 pad, and both 5 pads can be found here. It contains the yellow tunnel to the Big Tree area that Lanky has to open. Three of the five Kasplats are located here.

Big tree area
This area has a humongous redwood tree, inside of which sleeps the Owl that Diddy Kong must race (only during the night). Around the tree is the Rabbit's house, a tree stump where Tiny Kong collects a Golden Banana and a seed, and Lanky Kong's Kasplat. The 4 pad is located here.

Enemies

 * Kasplat
 * Tomato
 * Dogadon (boss)

Day only

 * Klump
 * Shroom
 * Zinger

Night only

 * Bones
 * Bat
 * Kosha
 * Small Spider (during the mini-boss battle)
 * Giant Spider (mini-boss)

Trivia

 * This level was originally going to be in Rare's other Nintendo 64 game,  (where it was called "Fungus Forest"), but was instead added to Donkey Kong 64.
 * The lobby theme is based on the track known as "Advent" which has been found in Banjo-Kazooie.
 * The main theme for the level was originally composed for Banjo-Kazooie's predecessor, the canceled SNES game Project Dream. It was titled "Temple" by the composer of both Banjo-Kazooie and Donkey Kong 64, Grant Kirkhope.
 * There is a 5-Banana Coin in this level that went undocumented until January 28, 2017, seventeen years after the game's release. The collectible was first brought to public attention when Isotarge, a member of the game's speedrunning community, datamined the game and found data for a 977th Banana Coin located here; prior to his findings, they had assumed that there were only 976 of them in the game. The coin in question can be found in a dirt patch hidden in a patch of tall grass surrounding the DK Barrel just outside one of the mills.