Goomy, the Soft Tissue Pokemon, is a pure Dragon type. It can be found on Route 14 at the maximum level of 32. When it reaches level 40, it evolves into Sliggoo. To evolve again, it has to reach level 50, but that’s not all. There’s a new method of evolution in the sixth generation. As of now, it only applies to Sliggoo and its evolution, but it could apply to more Pokemon in the future. Anyway, Sliggoo has to be reach at least level 50 when it is raining in the overworld. I don’t know this for a fact, but at all times in Kalos, there is a place where it is raining. It will only rain for a set amount of time, and after that it will be raining somewhere else. However, if it is raining on a route where the Pokemon are rather weak, there are two things you can do to still get the experience points you need. Most routes have bodies of water, meaning that if you have a Super Rod, you can find stronger Pokemon than you probably would on that route just by walking around on the grass. Keep in mind that at Route 15 is around where the Pokemon you find by using a Super Rod are around the same level of the Pokemon in the grass. As a second option, if your Sliggoo is already at least level 49, you can just use a Rare Candy to level it up. As long as it is raining in that place, it will evolve. Rain caused by a move (Rain Dance) or an ability (Drizzle or Primordial Sea) will not work. Once your Sliggoo evolves, it will become Goodra, the Dragon Pokemon (I’m not kidding, this thing’s species is literally Dragon). But should you get a Goomy?
I don’t mean to offend any Dragon type users, but with the addition of the Fairy types, Dragon types have lost their usefulness. Dragon types are only super effective against themselves. But it would be much easier to get a Fairy type Pokemon if you want to take on Drasna. Dragon types are not completely useless in this generation, as Drasna has a Dragalge. Dragon types are still tough and can take a Dragon Pulse better than a Fairy type can take a Sludge Bomb from Drasna’s Dragalge. Even then, you may not even have to worry about that if your Goodra is powerful and fast enough. Goodra for the most part are faster than Dragalge, and yours will already have the opportunity to learn some Dragon moves such as Dragonbreath and Dragon Pulse. Those are both special attacks (Goodra’s base special attack is 110 while Dragalge’s base special defense is 123). Even if you still don’t want a Dragon type, I’ll leave you with another good quality of Dragon types: they resist several types such as Grass, Fire, Water, and Electric. In fact, one of Goodra’s regular abilities is Sap Sipper, which makes it not only immune to Grass type attacks, but they multiply its attack by 1.5. Its other ability is Hydration, which is really only useful if you it is raining or you have a Pokemon capable of making it rain. Even then, it’s only useful if your opponent is trying to put status effects on you. Its hidden ability is unique and is arguably more useful than Hydration but less than Sap Sipper. This thing’s abilities aren’t all that great; Even Sap Sipper only works if your opponent has Grass moves and your Goodra has regular attacks. But its hidden ability can be useful if you have fast opponents and they have contact moves. This ability makes any Pokemon that makes direct contact with Goodra have their speed reduced by a third. For instance, any Pokemon with a speed of 201 will have a speed of 134 instead. I’d like to point out that there are other Dragon types that can be found in Kalos, so if you don’t like Goodra, you can get a different Dragon type.
Fun Fact: Goodra’s base stats are all two times Goomy’s base stats.