Assuming you don't already have a dragon dance Larvitar/Pupitar/Tyranitar, you need a female Larvitar/Pupitar/Tyranitar and a compatible male with dragon dance.
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The only compatible male that learns dragon dance by level up is Axew, which you can find in Granite Cave using the DexNav.
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Charmander, Lapras, and Totodile are also compatible, but they can learn dragon dance only as an egg move.
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