I think there's two.. Fissure.. TM 50 i think.. and Horn drill.. horn drill can be learned by rhydon. The last 1 hit ko move is sheer cold
sheer cold, fissre, guilatine and horn drill
I think its Horn Drill or some thing
horn drill is not a TM in Pokemon platinum.
Horn drill,Sheer cold,Fissure,Guillotine. These move make foe Pokemon faint regardless of its current stats but has an accuracy of 30%:)
There is no such TM called horn drill.
Rhyperior can learn very powerful moves like Mega Horn, Rock Wrecker, and Horn Drill (a 1-hit KO move).
Horn drill is not a TM in diamond only in red and blue.
Fissure will not hit flying type Pokemon as it is a ground type move, by that same token it will not hit Pokemon with the ability levitate. Guillotine and Horn Drill will not hit ghost type Pokemon as they are a normal type move. So Fissure can hit Ghost types, just not those with levitate, and Guillotine and Horn Drill can hit Flying types. Still, given the chances of actually hitting with these one hit KO-moves, and the ability sturdy, you'd probably be better off just using Crunch or Thunderbolt.
Unfortunately, Nidoking doesn't learn Horn Drill at all. In order to have your Nidoking learn Horn Drill, you'll need to level up your Nidorino to level 46 (you learn Horn Drill at that level) and then evolve it into a Nidoking.
There are three that I know of. Horn Drill (Rhyperior) Fissure (Groudon) Sheer Cold (Kyogre)
Nidorino Learns Horn Drill at level Level 53 but that is only in firered/leafgreen have you got a specific game?