Neither.
no
Ninjask can be taught TM28- Dig.
It depends on what generation. There are a lot. >.< Just kidding. Diamond and Pearl, right? So... By leveling up Ariados, Wurmple, Ninjask, Kricketot, Burmy, Wormadam, Mothim, Combee, Skorupi, Drapion, Yanmega By breeding If the father was.... Paras Ariados, Ninjask, Yanmega Ledyba Ariados, Ninjask, Yanmega Venonat Ariados, Ninjask, Yanmega Nincada Ariados, Ninjask, Yanmega Surskit Ariados, Ninjask, Yanmega
no
no but shedninja can.
Originally, Horndrill was a TM07 in Generation One, the games Red, Blue, and Yellow. The TM07 has changed with Generations, because in Generation Two, it became Zap Cannon, then in the Third and Fourth, became Hail instead. So no Horndrill TM in Pokemon Diamond, I'm afraid. But you can get Pokemon migrated from the GameBoy Pokemon Cartdriges that learn the move Horndrill. Some of them are Nidoran, Rhyhorn and Rhydon, and Seaking and Goldeen. Have fun!
Ninjask or Shedinja.
It probably is a egg move.
Generation I: Level 48Generation II: Level 49Generation III: Level 49Generation IV: Level 47Generation V: Level 47
If you level it up to level 45 you will be able to let it learn dig, but remember you'll have to delete a move to learn it.
Nidoking doesn't learn Horn Drill by level. Its previous evolution, Nidorino, does, which learns it at level 46. You'll have to level up a Nidorino until it learns Horn Drill, then evolve it to Nidoking.
no ,but it might learn by breeding