Onix is one of the most important early-game Pokemon in Pokopia thanks to its Bulldoze and Crush specialties. You need Bulldoze to rebuild the Pokemon Center, and Crush is essential for breaking rocks, mining ores, and uncovering fossils. Getting Onix requires completing the multi-step "Yawn Up A Storm" questline in the Withered Wastelands.
Step-by-Step Walkthrough
Find the Trapped Onix
Head to the cave northwest of the Pokemon Center in the Withered Wastelands. You will find Onix trapped behind hardened clay that cannot be broken yet. Note the location and move on.
Talk to Professor Tangrowth
Speak with Professor Tangrowth, who explains that the clay blocking Onix can only be softened by rain. He directs you to the beach ruins to find a way to make it rain.
Build the Seaside Tall Grass Habitat
Go to the beach area and build a Seaside Tall Grass habitat to attract Slowpoke. You need 4 Tall Grass placed in a 2x2 arrangement adjacent to ocean water (at least 2 ocean water tiles).
Guide Slowpoke to the Pokemon Center
Once you befriend Slowpoke, you need to guide it from the beach back to the Pokemon Center area. This may require building stairs or ramps over terrain gaps, and watering any patches of dry ground along the path so Slowpoke can traverse comfortably.
Raise the Humidity Level
To trigger rain, the region's humidity must be high enough. Increase humidity by: watering dry ground with Water-specialty Pokemon, planting seeds using Grow-specialty Pokemon, breaking open water plugs (sealed water sources), and building fountains or water features.
Build the Rain Dance Site
Construct a Rain Dance Site habitat, which requires: 2 Castform Weather Charms (Rain) and 1 Plate of Food. Place these items together to form the habitat. This is the ritual site that enables rain to be summoned.
Trigger the First Rain with Slowpoke
Bring Slowpoke to the Rain Dance Site and use its Yawn specialty. Slowpoke's Yawn triggers a humidity surge that causes the first rainfall in the Withered Wastelands. The rain begins to soften the clay in Onix's cave.
Trigger the Second Rain with Kyogre
The first rain is not enough to fully soften the clay. You need a second, stronger downpour. Kyogre appears as part of the questline progression - interact with it to trigger a massive rainstorm that fully saturates the clay blocking Onix.
Free Onix from the Cave
Return to Onix's cave. The hardened clay is now soft enough to break. Use Rock Smash (from any Pokemon with the Crush specialty, or Slowpoke in this context) to shatter the softened barrier and free Onix.
Build the Smooth Tall Grass Habitat
Now that Onix is free, build its preferred habitat to officially befriend it. The Smooth Tall Grass habitat requires: 4 Dry Tall Grass arranged in a 2x2 pattern, plus 1 Smooth Rock placed nearby. Dry Tall Grass is the default terrain in the Withered Wastelands, and Smooth Rocks are found near rivers and coastlines.
Onix's Specialties
- Bulldoze - Flattens terrain and is required to rebuild the Pokemon Center. This is a critical progression gate, so getting Onix early unlocks the 3D Printer and other center facilities.
- Crush - Breaks rocks, mines ore deposits, and uncovers fossil fragments. Essential for gathering Stone, Iron Ore, Gold Ore, and other materials.
Tips
- This questline is effectively the main story of the Withered Wastelands region. Do not skip side objectives - they contribute to the humidity level you need.
- Build water features and plant as many seeds as possible while exploring to passively raise humidity.
- The Smooth Rock for Onix's habitat is often found right along the riverbanks in the Wastelands - check near water.
- Once you have Onix, prioritize rebuilding the Pokemon Center to unlock the 3D Printer, shop, and other services.