Get a ditto and a leafeon and you will breed eevees. Then evolve them with a leaf stone. You can breed eevees with any evolved forms. It is not possible to hatch eggs as leafeons.
Clefairy's Egg Group is Fairy, so any Pokemon with the same Egg Group can breed with Clefairy, including Ditto, which has its own Egg Group.
Rotom is in the Amorphus egg group, so it can breed with any Pokemon in that egg group.
jigglypuff and ditto can and will have an egg if left in daycare for long enough. only legendary Pokemon and Pokemon in the -no egg- group will not produce an egg...being in the fairy egg group, jigglypuff will produce an egg
No.
Eevees
put it in day care with another normal type and hatch an egg(evee has to be female)
Girl Eevees are rare. Because more than 95% of the time boy Eevees hatch instead of Girls. Out of my overall 60 Eevees, 55 are boys. But it is possible.
It will be luck because i have 33 Eevees and 27 of them are boys. Boy Eevees are more common.
trade
No, unfortunately, you can only get more eevees in crystal version is to breed one.
Yes. All eevees can matewith all other eevees in diamond, pearl, and platinum.
umbreon
Yes they are and in Evolution too.
Breed with a Ditto.
Get a ditto and a leafeon and you will breed eevees. Then evolve them with a leaf stone. You can breed eevees with any evolved forms. It is not possible to hatch eggs as leafeons.
Clefairy's Egg Group is Fairy, so any Pokemon with the same Egg Group can breed with Clefairy, including Ditto, which has its own Egg Group.