I'd like to nominate Ditto.
Design-wise, it is just a pink blob of goo that a 3-year-old could draw, and it has not changed at all since Gen 1 in that regard.
Even its movepool has remained shallow, as it consists entirely of Transform and, barring glitches, nothing else in the entirety of all six generations.
Its stats are also incredibly poor, at 48 each, and as if that weren't bad enough, its one use in-game, being a sex slave to the Day Care Pokémon, is rendered completely invalid by its inability to pass down moves/abilities to its offspring.
Obviously, Ditto gained a huge buff in Gen 5 thanks to its Dream World Ability, Imposter.
The problem is that this makes Ditto just as strong as your opponent - a complete copy. So you have to depend on your opponent doing something strong for this to work.
And since most people know what their own Pokémon's weaknesses are, even that won't work for long.
Design-wise, it is just a pink blob of goo that a 3-year-old could draw, and it has not changed at all since Gen 1 in that regard.
Even its movepool has remained shallow, as it consists entirely of Transform and, barring glitches, nothing else in the entirety of all six generations.
Its stats are also incredibly poor, at 48 each, and as if that weren't bad enough, its one use in-game, being a sex slave to the Day Care Pokémon, is rendered completely invalid by its inability to pass down moves/abilities to its offspring.
Obviously, Ditto gained a huge buff in Gen 5 thanks to its Dream World Ability, Imposter.
The problem is that this makes Ditto just as strong as your opponent - a complete copy. So you have to depend on your opponent doing something strong for this to work.
And since most people know what their own Pokémon's weaknesses are, even that won't work for long.