So, what are some of your favorite bad Pokemon sprites from past generations? A lot of people bring up the Gen 1 sprites (including those from Pokemon Green, which were really a sight to behold), but later generations also had some worthy contenders. Heck, there's even an article about it on Smogon:
Gah, Jolteon looks absolutely hideous HG/SS!
Anyway, go ahead and post examples of old sprites you found noteworthy, for all the wrong reasons.