Kabbu, the beetle, asks Maki for permission of exploration, and gets rejected. However, Vi soon joins him and battles Maki, who eventually trusts them and gives them the explorer's permit. They then head in Snakemouth Den to begin their exploration. They solve a few puzzles in the caves with their field abilities and find a Mushroom at the end of the Den. Picking it up causes the team to fall into a trapdoor, at where they find Leif, the Icicle moth, being trapped in a web. Spuder then emerges from darkness, scaring Vi away, and traps Kabbu in a cocoon as well. Fortunately, Vi reappears quickly and saves both heroes from the spider being via her beemerang. They then escape though a crack in the wall. As the team make their way deeper into the cave, they get abushed by a pack of Jellyshrooms, and Leif displays his ability to use ice magic, of which even he wasn't aware of. The explorers use their abilities to reach the depths of Snakemouth. The Ancient Mask is found there. As soon as Vi picks it up, a trap in the room is activated, causing it to start flooding, and Spuder appears again, but was frozen by Leif and becomes vulnerable to attacks. The team finishes Spuder off, and are washed away by the current from the trap. They soon pick themselves up near a cave (the entrance of Golden Path), and finally return to Ant Kingdom City safely with the mask.
- Hard Mode
- HP Plus
- Poison Defender
- Poison Resistance
- In the demo, Spy Specs was in Poison Defender's place.
- This is the only chapter alongside Chapter 7 to not mention its Main Locale in its chapter title.