No because there is no clock in leafgreen you must trade evee to a game with an internal clock to make it evolve to evee those games are ruby, sapphire and emerald also heartgold, soulsilver, diamond, pearl and platinum.
You can't leafeon doesn't exist in leafgreen.
vulpix,growlite and evee
evee can evolve into any of its forms in leaf green.all you have to do is to buy the evulation stone you want and use it on evee
Trade it to ruby,sapphire or emerald have them evolve your evee at night then give it back to leafgreen.
evee can evole into three things in firered and leafgreen. it can evolve into flareon if you use the fire stone, jolteon if you use the thunder stone, or vaporeon if you use the water stone.
It dosent evolve into anything because its already evoled
poliwhirl, evee and staryu. that's all i know there may be more.
Umbreon-High Friendship 8:00pm-3:59am Espeon-High Friendship 4:00am-7:59pm
No because leafgreen has no in game clock feature so to get umbreon you need to train an evee in a game that has an in game clock such as ruby or diamond then once evee has max friendship it will evolve to umbreon during the night time.
Evee can be obtained only from firered and leafgreen and Pokemon xd gale of darkness.
You have to make it happy, with lots of items like protein,calcium and stuff and then lvlit up in the evening/night then it will evolve, but you do need some patience of course, good luck! :)
You can't get evee in colosseum get one from xd gale of darkness or firered and leafgreen.