Unown (BW) is pretty great.
https://www.smogon.com/dex/bw/pokemon/unown/
Magikarp (SM) is worth a chuckle.
https://www.smogon.com/dex/sm/pokemon/magikarp/
There was also a write-up for Noctowl in one generation (I THINK it was SM) that consisted entirely of, "Don't use Noctowl," but it's been replaced by a serious write-up that amounts to about the same. Boo.
Oh, and Spinda (XY):
https://www.smogon.com/dex/xy/pokemon/spinda/