Meowth/Nyase
Meowth is the main Pokémon of Team Rocket, and the most irritating of everyone on the show. He's rude, loud, and thinks he knows everything. If his teammates say something stupid, he slashes their faces with his claws (which usually makes him end up in more pain). And he's got a serious grudge against Pikachu.
Despite his annoyingness, he's one of my favorite Pokémon. First of all, he's a cat. Very cute. His coloring reminds me of a Siamese, and he has that nasty attitude (no offense to anyone who owns a Siamese, but I've had bad experiences with them). And he's got good attacks. He defeated Onix, which is pretty impressive. I just wish he'd evolve into Persian... but then he just wouldn't be the same.
I know his background fairly well. He used to be a normal Meowth, that couldn't talk and walked on all four legs. Then he fell in love with another Meowth, who I guess didn't like him. He wanted to impress her, so he taught himself to walk on his hind legs and speak the human language. Then I think the girl Meowth didn't like it, thought he was becoming too much of a human, and went with a Persian instead. That was the point where he joined up with Team Rocket, I guess. He was assigned to Jessie and James, and it isn't until the St. Anne episode that we find out he's been replaced by a Persian. He's had something against all Persians since then... And I know the Persian in the Paras episode definitely didn't help. I feel so bad for poor Meowth.
Even though he does hate Pikachu. He hated Pikachu since the second episode. I think it's a natural thing, what with Meowth being a cat and Pikachu being a rodent. But it definitely goes beyond that! Nearly every episode Meowth ends up thundershocked or something. Even though the mouse has saved his life before (remember, they tied him up in the giant Pokémon episode, and Pikachu untied him when the giant Pokémon attacked. That episode really brought out the real Meowth! But I think the biggest reason that he hates Pikachu is the fact that if Team Rocket can capture it for good, he can get his spot as top cat back. It's not HIS fault he's stuck on a loser team! He's asked to be switched to a different team before, and is always complaining about how bad the team is. If he was on a better team, I bet they'd have the Pikachu already!
There's more to him than just his rottenness, as we know from the Togepi episode. He cared for that egg better than Brock did! And it was almost like it was his own egg. If only he'd taken care of it longer. I'm impressed that he was able to keep James from eating it. Good thing he did, or there'd be no Togepi.
Wait, isn't that a good thing?