You can catch it in the central area the one you start in or get 6,000 coins in the game corner and buy one from the Pokemon exchange next to the game corner the middle area is the Pokemon exchange.
you can not catch scyther in Pokemon ruby,emerald or sapphire . you have to trade them from Pokemon fire red or leaf green.
Chansey, Scyther, Tauros, Kangaskhan and Dragonair.
Trade It From Pokemon Fire Red Or Leaf Green
you can only aquire one from the game corner as a prize and you can get one in the safari zone if you are very luck you will see one in the first patch of grass you see when you first walk in the safari zone
There is: Paras, Nidoran, Chansey, Scyther, Psyduck, Goldeen, Magikarp, Dratini, Kangaskhan, Parasect, Doduo, Exeggcute, Tauros.
You can get it in Leaf Green in the safari zone but it is hard to find, so it would be easier to trade it from Fire Red. you could also get it from the game corner as a prize trade in your coins for it. PS i pone at Pokemon my team is rhydon metagross scyther sceptile salamence toxicroak
in area one you can find scyther, in area e you can find chansey,in area two you can find kangaskhan and in area four its tauros
you find kangaskhan in area 2 of the safari zone in Pokemon leaf Green ... not sure in fire red sorry
Scyther is Bug/Flying type. I would suggest getting a Fire type (Ex Growlithe) or an Electric type (Ex Mareep).
The Pokemon 123 in leaf green is scyther, i think you can get it by trading it from fire red...
use a super rod in the ponds or you could get it at the game corner at celadon city
The Safari Zone is in Fushia City.