Gen 9 Doubles UU

Mimikyu @ Mental Herb
Ability: Disguise
Tera Type: Water
EVs: 248 HP / 252 Atk / 8 Def
Brave Nature
IVs: 0 Spe
- Trick Room
- Will-O-Wisp
- Play Rough
- Shadow Sneak
Thanks to it's great ability in Disguise and an immunity to Fake Out, Mimikyu is currently one of the most reliable Trick Room setters in the format, and is a great fit for Semi-Room and Full-Room teams. Trick Room is excellent speed control in doubles, turning the tables against faster teams. Will-O-Wisp lets Mimikyu spread burns, crippling physical attckers. Play Rough is Fairy STAB, capable of OHKOing Gallade, Meowscarada and Breloom (assuming the latter two are not holding a Focus Sash). Shadow Sneak is priority STAB, finishing off fast opponents both in and outside of Trick Room.
Mental Herb allows Mimikyu to ignore Taunt once. With the combination of Mental Herb and Disguise, it is very hard to knock out Mimikyu before it can set up Trick Room early game (especially when it's paired with a Fake Out user such as Hariyama, another excellent Pokémon on Trick Room teams). Tera Water allows Mimikyu to survive Scizor's Bullet Punch or Tinkaton's Gigaton Hammer in a pinch.