Name: Meowth
Availability:Very early on, right by the school. 30% encounter rate is very solid.
Stats: And here's where the problems begin. Meowth has garbage stats, even as a Persian. It's only solid stat is its speed. Everything else is mediocre at best and pathetic at worst.
Typing: Pure dark type is sorta nifty... but not here. Not with fighting types/bugs/fairies around every turn, and Meowth has very little to deal with them.
Movepool: Okay, you got Fake Out and Bite for early on, and arguably Hidden Power depending on what type it is... and that's it. You're not running any coverage until Aerial Ace/U-turn, and later on Power Gem, with the former being in the mid to late 20's most likely. Until then, Bite is your best option, and while it starts off okay... things rapidly drop off a cliff.
Notable Battles:
Captain Ilima: Yungoos is manageable, but Smeargle will make you cry. whatever coverage move it has, ontop of tackle, is going to hurt.
Totem Raticate/Gumshoos: They hit harder than you, are bulkier than you, and bite hax can only get you so far until you get pounded into the dirt.
Hau: Early matches, it's a mixed bag. Later on once Raichu appears is where Meowth starts to shine, easily taking down the rodent with Fake Out+Bite or whatever dark move you have by then. Starter is iffy, and eeveelution depends, though most are going to hit you harder than you hit them.
Hala: NO.
Gladion: Zubat is easy, as is Golbat thanks to Power Gem. Sneasel and Weavile also drop to Power Gem, but beware the Lucario. Type Null and Silvally are too bulky and hit too hard.
Totem Wishiwashi: Once again, bite hax can only get you so far before you get dropped by Water Gun
Totem Salazzle: Flame Burst>Meowth
Totem Lurantis: NO
Plumeria: You don't have Power Gem yet, so Golbat is better left to someone else. If you have Persian by now, it should be able to handle Salandit, especially with a good HP type. Later on, the fight does get easier thanks to Power Gem, but Persian might be taking a hit or two...
Olivia: NO. Nosepass WILL live a hit and paralyze you, and Boldore WILL try to lower your accuracy with Mud Slap. Also, Lycanroc hits WAY too hard.
Molayne: Metang is doable, but Persian is going to be taking some hits from it first. Skarmory and Dugtrio are technically doable, especially with Snarl, but there's better options.
Totem Vikavolt: Even with Power Gem, NO. Vikavolt will live a hit and Bug Bite you for massive damage, and the Charjabug love to cripple you.
Guzma: Golisopod used First Impression!
Totem Mimikyu: NO. Play Rough is going to murder Persian before it can even do damage to it.
Team Skull: Perisan does well here... but so does almost anything else.
Nanu: Sableye is manageable, but Krokorok and the other Persian are going to be hitting you harder than you hit them.
Team Aether: Faba drops like a rock to Persian, but considering how varied the mons they use are, be careful.
Lusamine: Clefable nukes you, Milotic nukes you, Mismagius dies, Lilligant nukes you, and Bewear nukes you. STAY AWAY FROM THIS CRAZY WOMAN.
Hapu: Persian can't hit hard enough, so it's going to be hurting, especially from now in. Nasty Plot sorta helps... but you gotta live a hit first, and that's a tall order, especially against Mudsdale and co.
Totem Kommo-o: NO
Elite 4: Acerola is doable with a little help, you can sweep through Kahili with Nasty Plot+Thunderbolt/Power Gem, Hala and Olivia are NO.
Professor Kukui: Lycanroc hits harder than you, Snorlax laughs at you, Ninetails murders you, Magnezone has Mirror Coat to screw you over, Braviary can live a hit and smash you apart with Brave Bird, and only Decidueye is doable among the starters.
Additional Information: Meowth has two primary abilities for use: Fur Coat, and Technician. You are either going to have a decently bulky pokemon with bad offenses, or a decently hard hitting mon with paper thin defenses. You can't get both, and even with Technician, Meowth just can't last into the late game outside of laughing at Hau's Raichu. It struggles to hold a solid niche for itself due to how the game is laid out, and if you try to make it do more than it realistically can, you will find yourself with a dead cat more often than not.