Background Information - When creepy and cuteness combine forces to create Espurr, one of the most iconic Pokemon of Gen 6
This is one of the cases where the evolution line is more well-known for it's pre-evo than it's final-evo and for this case it's none other than Espurr who is often viewed as both one of the creepiest and cutest Pokemon ever to be created. The most famous trainer to ever own a member of the Meowstic Evolution Line is none other than Emma who worked for Looker as an assistant or possibly more familiarly as the brainwashed test subject, Essentia. Emma owns an Espurr that truly care for each other, having making an appearance in Pokemon Generaitons where Espurr valiantly stands up to Essentia, wanting her trainer back. In Pokemon Adventures, in the epitome of cuteness, we see Emma following the main heroes after Mimi the Espurr secretly enters their Kangaskhan's pouch, befriending the baby Kangaskhan. As for Meowstic, it's well-known to be Olympia's very own signature Pokemon which made quite a huge impression on viewers during their Future Sight battle against Ash. There's also the trainer Astrid who also made quite an impression with viewers who utilized a female Meowstic to battle Ash.
Well-Known Trainers to own the Espurr Line
Emma - Games, Generations, Pokemon Adventures
Olympia - Game, Pokemon Adventures, Anime
Astrid - Anime
Male
Meowstic the Dancer - Singles - Doubles
Meowstic
Item: Colbur Berry
Ability: Prankster
Nature: Bold (+Def,-Atk)
EVs: 252 HP/252 Def
Thunder-Wave/Yawn
Heal Bell
Fake-out
Psychic
Pretty straightfoward. Slows down enemies, heals statuses. Fake-out enemies.
Meowstic the Mime - Singles - Doubles
Meowstic
Item: Light Clay
Ability: Prankster
Nature: Bold (+Def,-Atk)
EVs: 252 HP/252 Def
Reflect
Light Screen
Thunder Wave/Yawn
Psychic
Also pretty straightforward. Reflect and Light-Screen support.
Meowstic the Card Player - Singles - Doubles
Meowstic
Item: Choice Spec/Choice Scarf
Ability: Prankster
Nature: Modest Nature (+Sp. Atk/-Atk)
EVs: 252 Sp. Atk/252 Spe
Trick
Psychic
Thunder Wave
Calm Mind
This is one of those sets where you adapt to new situations with or without Choice Spec/Choice Scarf. With the Choice items, you can go on the offensive. Without it, you can use Calm Mind and spam that Thunder Wave.
Meowstic the Sleight of Hand - Doubles Only
Meowstic
Item: Focus Sash or Light Clay
Ability: Prankster
Nature: Bold (+Def,-Atk)
EVs: 252 HP/252 Def
Helping Hand
Thunder Wave/Light Screen
Heal Bell/Reflect
Ally Switch
Pretty straightforward helper set.
Female
Meowstic - LISTEN YOU LITTLE PUNKS! - Singles and Doubles
Meowstic
Item: Focus Sash
Ability: Competitive
Nature: Timid (+Spe,-Atk)
EVs: 252 Sp. Atk/252 Spe
Psyshock/Hidden Power Fighting
Calm Mind
Stored Power
Thunder Wave/Psych Up/Fake-Out
Gonna be hoenst. I think Meowstic's competitive ability may work better as a lead in doubles because you have a higher chance to find intimidate spammers On the other hand though, Meowstic is a very frail Pokemon with a limited moveset and looks like it works more in Singles. Anyways, this is the stored power set.
Meowstic - DON'T LET THE BEDBUGS BITE! - Singles and Doubles
Meowstic
Item: Focus Sash
Ability: Competitive
Nature: Timid (+Spe,-Atk)
EVs: 252 Sp. Atk/252 Spe
Psyshock/Hidden Power Fighting
Yawn
Dream Eater
Calm-Mind/Thunder Wave
Straightforward. Yawn a target. Use Calm Mind if they switch-out or they don't. If they don't, lucky you. You got a Dream Eater target. Also HIdden Power Fighting in-case you encounter any Dark-types.