What Pokemon use dragon tooth?

Answer 1

I assume you mean the Dragon Fang. It's a hold item so any pokemon can use it, but in the wild a Dragonaire or Dragonite may be holding it.

If you mean the evolutionary hold item the Deep Sea Tooth, a Clampearl that holds it while being traded will evolve into a huntail. There is only 1 and choosing it means loosing the Deep Sea Scale.

The Dragon Scale will evolve a Horsea into a Seadra the same way the deep Sea Tooth evolves Clampearl. A Horsea, Seadra, kingdra, Dratini, Dragonair, Dragonite, Bagon, Shelgon, or Salamence may be holding one.