While many Pokemon in Pokemon Legends: Z-A make the Wild Zones their homes, ones like Dratini tend to spawn in specific spots on rooftops. The thing about this character that I’ve found is, it also likes to pop up on roofs that you can’t reach until you’ve unlocked the Roto-Glide ability in the game. (This comes up once you start get into helping Rogue Mega-Evolved Pokemon.) Once it does, I found there’s one particular spot that’s best for Dratini hunting.
Where do I find a Dratini in Pokemon Legends: Z-A?
The most reliable and easy-to-reach spawn is not far from Jaune Plaza and Wild Zone 8. There’s a building to the northeast of it that has a spot where there’s a normal rooftop patio, but then another part that’s slightly lower. The Dratini will always spawn in the garden there, so you can sneak up behind it and strike with a Poke Ball from above.
Here’s the exact spot on the map:

Now, Dratinis are skittish Pokemon in Pokemon Legends: Z-A, so it will almost immediately flee after it senses your presence. (The only exception is if it is an Alpha.) I recommend having Ultra Balls when trying to catch one. If you miss, then wander away for a while, perhaps even fast traveling to another location on the map and returning, to cause it to respawn. If you stay in the same spot on the roof and just wait for time to pass and a new day to start, I found it won’t respawn during the transition. You actually need to step away.
If you do catch your Dratini from this spot, it should be around level 27-29. If it shows up as an Alpha, it will be closer to level 40.
Pokemon Legends: Z-A is available for the Switch and Switch 2.