Dude, I really hate to say this to you but the EVs are wrong. The Muk has 255 HP, 82 Atk and 173 Spe. It's missed out on a crucial 4 EVs (plus I'm a lot less likely to get an offer from it). I'm gonna have to ask if you can redo it but with the exact EVs of 252 HP / 80 Def / 176 SpD.
Since I know how time consuming EV training can be (especially without Pokérus) and how annoying this must be for you, I will give you a random Pokémon from my thread.