Ever stared at a purple, cocoon-shaped blob in your Game Boy or Switch screen and wondered if you’re doing it right? You aren't alone. Cascoon is one of those Pokémon that feels like a bit of a trick. You catch a Wurmple, you level it up, and suddenly you’ve got this spikey, slightly grumpy-looking shell. But what does Cascoon evolve into? It’s not just a matter of "when" it evolves, but "why" it became a Cascoon in the first place.
Cascoon evolves into Dustox. That’s the short answer. At Level 10, that purple shell cracks open and out pops a Poison/Bug-type moth with neon-green wings and a penchant for nocturnal mischief. If you were hoping for the elegant, white-winged Beautifly, I’ve got some bad news. You’re on the wrong evolutionary branch.
The Wurmple Gamble: Why You Got a Cascoon
It feels random. Honestly, for years, kids on the playground argued that it depended on the time of day or what move you used last. They were wrong. The split between Cascoon and Silcoon is determined the very second that Wurmple is generated by the game's engine.
It’s all about Personality Values. Every Pokémon has a hidden string of numbers called a PV. You can’t see it. There’s no "check stats" screen that will show you the raw data. The game takes that number, performs a quick bit of math, and decides right then and there: "This one is a Cascoon."
Specifically, the game looks at the upper 16 bits of that 32-bit PV. If the result of $(PV \pmod{10})$ is greater than or equal to 5, you get a Silcoon. If it’s less than 5, you’re looking at a Cascoon. It’s a literal coin flip that happened before you even threw your first Poké Ball. Because you can’t change a Pokémon’s personality value, you can’t "force" a Wurmple to become a Cascoon. You just have to catch another one if you wanted the other moth.
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Dustox: The Toxic Moth at the End of the Tunnel
So, your Cascoon hit Level 10. The screen flashes white. The music gets dramatic.
Meet Dustox.
Unlike its cousin Beautifly, which is a Bug/Flying type, Dustox leans heavily into the Poison side of things. It’s a defensive pivot. While it’s never going to be the heaviest hitter in a competitive Master Ball Tier team, Dustox has a specific niche that makes it way more interesting than people give it credit for.
It’s got a base stat total of 385. That's not high. In fact, by the time you reach the late game in Pokémon Emerald or Brilliant Diamond, Dustox usually ends up sitting in a PC box. But early on? It’s a wall. With base 70 Special Defense and 90 base Defense, it can soak up hits from early-game Normal and Grass types like a sponge.
Why Cascoon is actually better for the early game
Most players want the "pretty" one. They want Beautifly because it looks like a hero. But if you’re playing a Nuzlocke challenge—where if a Pokémon faints, it’s dead—you actually want Cascoon.
Think about the first few gyms in the Hoenn region. Roxanne uses Rock types. Brawly uses Fighting types. A Dustox evolved from a Cascoon resists Fighting moves 4x over. It’s a brick wall against Brawly’s Makuhita. While Silcoon is busy being fragile, Cascoon is preparing to become a tanky moth that can spread Status effects.
The Moveset: More Than Just String Shot
Cascoon itself is pretty boring. It knows Harden. It might know Iron Defense if you’re playing later generations. It just sits there.
But once it becomes Dustox, the movepool opens up in a way that’s actually kind of gross (in a good way). We’re talking about:
- Toxic: The bread and butter. You wear the enemy down.
- Moonlight: Only available in certain generations, but it allows Dustox to heal based on the weather.
- Quiver Dance: This is the game-changer. It raises Special Attack, Special Defense, and Speed all at once.
- Venoshock: If you’ve already poisoned the enemy with Toxic, Venoshock deals double damage.
Common Myths About Cascoon Evolution
Let's clear the air. No, Cascoon does not evolve into Venomoth. They look similar, sure. They’re both purple moths. But Venomoth is a Kanto classic, evolving from Venonat. Dustox is its own thing entirely.
Another weird one: "If you level it up at night, it becomes Cascoon."
False.
This myth probably started because Dustox is a "nocturnal" Pokémon in the lore. It flies toward bright lights at night and strips the leaves off trees. But the game mechanics don't care about the clock for this specific evolution. Day or night, a Cascoon-coded Wurmple will always be a Cascoon.
The Evolution in Different Games
The process hasn't changed much since 2002. Whether you’re playing the original Ruby and Sapphire or the 2022 Pokémon Legends: Arceus, the Level 10 requirement stays the same.
In Pokémon GO, things are a little different. You don't have levels in the traditional sense. You need 50 Wurmple Candy to evolve your Cascoon into Dustox. But the Wurmple-to-Cascoon split? Still random. You just have to keep evolving Wurmples until the "luck of the draw" gives you the cocoon you need for your Pokédex.
In Pokémon Legends: Arceus, the Cascoon is actually much more "present" in the world. You can find them hanging from trees in the Obsidian Fieldlands. If you catch one wild, you skip the Wurmple guessing game entirely. It’s the easiest way to ensure you get a Dustox without wasting candies or time on a Silcoon you don't want.
Is it worth keeping?
Honestly? Usually no.
Unless you have a deep emotional attachment to the "Toxic Moth" aesthetic, Dustox falls off hard after the third or fourth gym. Its stats just can't keep up with the power creep of mid-game Pokémon like Gardevoir or Manectric. However, if you're doing a "Bug-Only" run, Dustox is your MVP for its ability to absorb hits while you heal your other team members.
How to use your newly evolved Dustox
If you’ve just evolved your Cascoon, don't just spam Confusion. Use its typing.
- Focus on Status: Use Poison Powder or Toxic immediately.
- Protect: Use the move Protect to let the poison damage tick up while you stay safe.
- Switch Out: Once the enemy is badly poisoned, swap to a stronger attacker to finish the job.
Actionable Next Steps
If you are currently holding a Cascoon and waiting for that evolution, here is exactly what you should do:
- Check its moves: If you’re in a later generation, make sure it has learned Iron Defense before it evolves; it helps with its survivability as a Dustox.
- Head to a low-level area: Don't try to grind Cascoon against heavy hitters. It only knows Harden. Put it at the front of your party, immediately switch it out for a stronger Pokémon, and let it soak up the "Exp. Share" points until it hits Level 10.
- Prepare for Brawly: If you’re playing a Hoenn-based game (Emerald, ORAS), keep that Cascoon/Dustox for the second gym. Its resistance to Fighting moves makes the fight trivial.
- Catch multiples: If you really wanted a Silcoon/Beautifly, stop leveling this one. Go back to Route 101 or the Obsidian Fieldlands and catch 3-4 more Wurmples. Mathematically, you’re bound to get the other branch within a few tries.