you either get it around 23 or use a dusk stone.
It evolves into Mismagius. you have to have a dusk stone. so that means you can only evolve Misdreavus in Diamond or Pearl
You cant in the wild but i think you can get a misdreavus in the lost tower after 8:00pm and evolve it.
Get a misdrevious in enterna forest,if you want mismagious use a dusk stone on misdreavious.
you have to trade it from pearl
It is suppose to evolve at the Level of 20,but if you want it to evolve later it can evolve anything after it is at Level 20.
It will evolve by level. Teddiursa will evolve into a Ursaring at level 30.
They evolve at level 36
It will evolve at level 36.
They evolve on level 40
it evolve on level on 64
Young couple Mike and Nat in the lost tower (route 209, just south of solaceon town) have a level 23 murkrow and a level 23 misdrevious. You'll win 2944 cash from them. I'm not sure what floor out of the lost tower they're on. Sorry. Search the five floors until you find a young couple on a date. Challenge them. (No idea why they're having a date in that graveyard) Hope this helped.
if you dont let it evolve at the required level of level 20. itll try to evolve at every level following.