In the Valcano on one of the 3 islands.
trade him
no
No
All starters, including Bulbasaur, can't be caught in Pokemon LeafGreen.
You can not catch it in leafgreen,but in firered you can.
i don't no i think at route 33
You can only get a Mareep by using a Wonder Card which is used in Mystery Gift and with the Wireless Adapter that alters the Pokemon inside Altering Cave allowing you to catch a Mareep, Teddiursa, Houndour, Stantler, Pineco, and Zubat (Which is the only Pokemon you can catch without Mystery Gift.).
You cannot catch aipom in leafgreen however you can in emerald or Pokemon colosseum.
No only firered can.
It is not possible to catch a Sunkern in Pokemon LeafGreen version. The only way to get one is to trade for it.
Gligar is a flying and ground type of Pokemon. The only way to get this Pokemon in LeafGreen version is to trade for it.
No you cant you can only get it in ruby version.
In the Valcano on one of the 3 islands.
trade
Nowhere.
trade him