Frog Forest is the ninth stage in Sonic Heroes. The stage is played differently for each team. There are Giant Frogs that can be found within the level, which have the power to create rain and make plants grow faster, allowing teams to progress through the level.
During Team Rose's version of Frog Forest, Big the Cat mentions that Froggy comes from the Frog Forest. This fact is backed up by the fact that the frogs here are very similar to Froggy in appearance, although much larger.
After destroying Egg Albatross in Bullet Station, the heroes go north to a canopy. Team Sonic goes through the forest to stop the Egg Fleet. Team Dark must go through the forest to make Eggman explain about the Shadow Android at the Egg Albatross crash. Team Rose now searches for Froggy and Chocola in addition to Sonic after concluding that Eggman stole them, and Team Chaotix must sneak through the forest while avoiding Eggman's robots and the giant frogs, the latter of which will alert the robots if they spot the Chaotix.
Mission
The regular/extra missions are:
Team Sonic: Get through the forest where the wild animals live! / Get to the Goal Ring within 5 minutes!
Team Dark: Get through the forest where the wild animals live! / Defeat 100 enemies!
Team Rose: Explore the forest where the frogs live! / Collect 200 rings!
Team Chaotix: Get through the forest without being detected by the frogs! / Hurry and avoid being detected by the frogs! (Within 4 minutes)
Rank requirements
The following is a list of requirements to attain a rank for each mission with each team.[1]
Normal Missions
Rank A
Rank B
Rank C
Rank D
Rank E
Mission 1
Team Sonic
35,000
32,000
28,000
25,000
<25,000
Get through the forest where the wild animals live!
Team Dark
45,000
40,000
35,000
30,000
<30,000
Get through the forest where the wild animals live!
Team Rose
40,000
38,000
34,000
30,000
<30,000
Explore the forest where the frogs live!
Team Chaotix
40,000
38,000
34,000
30,000
<30,000
Get through the forest without being detected by the frogs!
Extra Missions
Rank A
Rank B
Rank C
Rank D
Rank E
Mission 2
Team Sonic
38,000
35,000
30,000
28,000
<28,000
Get to the goal ring within 5 minutes!
Team Dark
14:00
14:30
15:00
16:00
>16:00
Defeat 100 enemies! (Time in minutes.)
Team Rose
3:30
4:00
4:30
5:00
>5:00
Collect 200 rings! (Time in minutes.)
Team Chaotix
42,000
40,000
36,000
32,000
<32,000
Hurry and get through without being detected by the frogs!
Trivia
This stage is similar to Ellinia in the MMORPG MapleStory in both appearance and music.
It is possible to get Team Rose over to Team Sonic and Team Dark's section of Frog Forest if the player skips the Goal Ring.
There are huge frogs in this jungle. Once they start to croak, it will start to rain and you'll be spotted easily. 
