The third generation introduced a lot of weak, single-stage pokemon that exist just to play with gimmicky game mechanics, but the fourth generation has basically just one, Chatot. It's a cute little music-note parrot with the signature move "chatter," which allows the player to actually record a sound or voice clip with the Gameboy Advance microphone and replay it to damage enemies. The fact that 90% of kids were going to say something dirty apparently didn't matter, and neither did giving Chatot any other function or advantage. It's surprisingly effective in the absolute lowest competitive tiers, but its signature move isn't even actually strong enough to justify itself.
Cute but lacking.