yes when you go find one of the sages at relic castle when you are almost where ghetsis is you can battle onix and sandslash. after you find ghetsis you can also fight volcarona
A black Onix is a shiny Pokemon, which is extremely rare.
relic castle
It can be found in the Relic Castle in Pokemon Black Or White
yes it evoles by happiness
In Pokemon Yellow Onix does not evolve, it is a one stage Pokemon.
If you mean,, what onix evolves into,, it's steelix,, but the is no Pokemon that evolves into onix
Unfortunately, you can't get an Onix in Pokemon Emerald. To have your own Onix, you need to trade it from FireRed or LeafGreen. Hope I helped :)
Onix is in Pewter City where Brock is.
Onix is a Rock/Ground type Pokemon.
You can only get an "onix" in Pokemon sapphire if you have a Pokemon version that has an onix then use a linking cable with other GBA to trade it and then you'll have an onix but "onix's" data can't be stored in your pokedex.NOTE:You can only trade with a Pokemon version that have the same region as your Sapphire has;HOENN REGION.
Please see the related link for info on the pokemon, Onix
If you mean Onix, nothing evolves into onix