At rock cave
Pokemon Tower Defense is 1st generation pokemon only, so no fourth generation or second generation evolutions (including Steelix). Therefore, Onix can't evolve.
In the tower outside the forest of the Kingdom of Onix (Rock Pokemon) and into the kingdom of Charzard (Fire Pokemon) and it's by the third tree after you duel the pokemon in the field. (Capture it if you want)
Onix is in Pewter City where Brock is.
I've always found a Butterfree level 15 to be enough, as Confusion hits his Geodude and Onix where it hurts: in their low special defense stats. You could also just keep trying until his Onix uses Bide, then use a move that makes his defense fall until he's finished biding.
Onix is #95 in the national pokedex, and it is a Rock-Ground type Pokemon.
ptdgames
Pokemon Tower Defense is 1st generation pokemon only, so no fourth generation or second generation evolutions (including Steelix). Therefore, Onix can't evolve.
beat it with a pokemon that has the advantage
In the cave place. I think it is lvl 3.
you beat the giant onix and show a guy a pikachu lv 42 and a electrod and you will get a shiny voltrob
Nothing.
well the only one i know of is one you can make. onix to steelix
In Pokemon Yellow Onix does not evolve, it is a one stage Pokemon.
in violet city walk around in the trees towards the nw and you will find the guy who will trade you it
If you mean,, what onix evolves into,, it's steelix,, but the is no Pokemon that evolves into onix
In the tower outside the forest of the Kingdom of Onix (Rock Pokemon) and into the kingdom of Charzard (Fire Pokemon) and it's by the third tree after you duel the pokemon in the field. (Capture it if you want)
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 :)