A good deal of the Gen 7 Pokémon. XD But really, it might have to be either Medicham, Garbodor, or Ferrothorn for me, though I'm sure I could think of a lot more.
Ahaha, I happen to really like this fish XD But I also happen to really like Feebas so I guess you could say I have a tendency to like the ugly fishes of Pokémon, pft. The one I find the ugliest has to be Togedemaru and Yanmega
If it's an ugly Pokémon that I don't like and absoluteky hate there's two, Trubbish and Palossand. Palossand probably mostlt hate it because it reminds me of that annoying monster in Kid Icarus and Trubbish is pretty obvious. It's a freaking garbage bag!
Mr Mime and Barbaracle are definitely the ugliest to me. Both of their designs are extremely off-putting and not nice to look at all. Chansey is kind of ugly as well, as is Blissey.
When making the downloadable dex a while ago, I kind of paused when I came to Qualot, and just sort of... stared at it for a while. I mean, really stared at it. Took a moment to contemplate this creature in its entirety. I don't think it's particularly ugly exactly, but... what is it? It's so... weird.
Literally all of the ultra beasts (except for Pheromosa and, I guess Poipole). Doesn't help that I already dislike them- but I just think they're ugly as hell (and overdesigned).
Like many others have said, Bruxish is just so ugly. However, I did some research and found out that it's actually based on Hawaii's state fish, the humuhumu nukunuku apua'a. Comparing the two, Bruxish's design actually makes a lot of sense. I still don't get why they added teeth, though. I remember when Spritzee was first revealed, I thought it was the most hideous thing ever. Now I find it absolutely adorable, so opinions do change. I still think Aromatisse is pretty ugly. I'm glad someone agrees with me on this! I thought they were fake leaks when I first saw them. However, no one can really say, "Those don't look like Pokémon," because, technically, they're not.
I cannot stand Guzzlord and I'm honestly surprised someone at Game Freak came up with that kind of design.