You have to see grass and then go in the grass and battle. It is usually Elekid for me but try to get a Pokemon in White Forest. If there is no grass then you can't catch Elekid and other Pokemon so just try to get grass. :)
You can catch magby in the white forest
You can catch Silcoon in White Forest.
White forest
White Forest
in white forest
white forest
You can only catch them in White Forest.
You can't catch it in Black, but you can catch it in White. In the White Forest.
In the white forest.
You catch it in white forest once you do a few missions.
In White Forest you but in Black you have to trade from White.
You can only catch it in White Forest. If you have black version, I cant tell you that.