Dugtrio @ Focus Sash
Ability: Arena Trap
4 HP/ 252 Atk/ 252 Spe
Nature: Jolly
-Stealth Rock
-Sucker Punch
-Protect
-Earthquake/Reversal
Honestly I saw the rampancy of Ambipom as a lead in UU as an opportunity to flesh-out some lead ideas, this Pokémon is the result of this. The main focus of this set is to beat-out Ambipom by protecting the first move from Fake Out, then Sucker Punch on their probable attack and outspeed them with Reversal, on the switch laying down Stealth Rock's, fairly simple in summation. Dugtrio can also take down the likes of Alakazam but that is a little more iffy, due to the probability of speed tie and then it becomes a game of chance, but with proper prediction you can hit it with SP x2 or Reversal and SP. Also with the ability of Arena Trap, Ambipom without U-turn are screwed and other common leads stand no chance in hell of escaping unscathed. If Dugtrio manages to live much past the initial battle then he can be used as a semi-revenge killer, assuming that Dugtrio will outspeed the opponent later in game.
After some suggestions, I have updated the set to Earthquake over Reversal due to the fact that EQ hits the likes of Alakazam for neutral damage and most common leads in UU have paper thin defenses anyways. Earthquake also allows Dugtrio to address more Pokémon in general, early and late game.
Edits in this format!