Where can you catch a flygon in Pokemon emerald?

Answer 1

In Pokémon Emerald, you cannot catch Flygon however you can find Trapinch in the desert area that is north of Mauville City which is also known as Route 111 and then you can raise Trapinch until it reaches the level of Level 35 which is when it will evolve into Vibrava and then you can raise Vibrava until it reaches Level 45 which is when it will evolve into Flygon.

Answer 2

Unfortunately, you have to catch a Trapinch first (you can get one from the desert region on route 111) and evolve it to lv 45.