Wobbuffet in depth
The doll that gets back up
The Japanese name, Sōnansu, comes from rakugo comedian Sanpei Hayashiya's catchphrase: “sō nansu, okusan”, roughly “that's right, ma'am”. Hayashiya would finish it by putting a hand to his forehead, which is exactly the doll's pose. Its pre-evolution answers back: Sōnano sounds like “really?”, so the two Japanese names form a conversation.
English takes a different route. Wobbuffet combines wobble with buffet, meaning to strike, and also sounds a bit like “why bother?”. Wynaut, in the same joke, is “why not”. The pun survives in translation, which does not always happen.
Shadow Tag before and after
For three generations, this line had the ability to itself: until the fifth generation, no other Pokémon could have Shadow Tag. That changed with the arrival of Gothitelle, which does a similar job — trapping the opponent and dismantling defensive teams — but has actual offensive moves and the same weakness against fast teams.
The other major change came in the sixth generation, when Ghost-types began ignoring all trapping abilities and moves. Before that, being trapped meant being trapped. The useful comparison is Dugtrio and its Arena Trap, which only catches Pokémon that are on the ground; Shadow Tag had no such exception, and that is precisely why it has been suspended and debated so many times.
Telepathy, its Hidden Ability, prevents it from taking damage from its partner's attacks in Double Battles. It is the option to choose when you do not want to trap anyone, and in practice it is almost never chosen.
Eight moves and one TM
The full level-up list fits on one line: Counter, Destiny Bond, Safeguard, Mirror Coat, Amnesia, Splash, Charm and Encore. All at level 1. There is no progression, nothing else to learn later, and the only compatible TM in Brilliant Diamond and Shining Pearl is Safeguard again, which it already knew. It is one of the poorest movepools in the Pokédex, and not through carelessness: any decent offensive move would undermine the whole idea of the thing.
In a normal playthrough, that leaves it in a very specific place. It is no use for making progress along routes, because it cannot weaken anything by itself without being hit first, and with 33 Attack, any physical attacks it might learn would be useless anyway. It is useful for breaking a deadlocked battle against an opponent that hits hard from one side only: switch in, take the hit and send it back doubled. Amnesia raises Special Defense by two stages and makes that wait longer; Charm lowers the opponent's Attack and does the same on the physical side.
Jessie's
Outside the games, the most familiar specimen is Team Rocket's. Jessie got it in a trade in the episode “Tricks of the Trade”, and from then on it made a habit of coming out of its Poké Ball by itself, at the worst possible moment, to announce its own name. The character lasted for hundreds of episodes doing exactly that gag, which is more or less what it does in battle: show up, take the hit and do nothing else.