They DO have wings (look up their pokedex entries on bulbapedia or wherever else), they're just hella short and they blend in with the rest of their bodies.
As someone else mentioned, I believe Mud Sport is meant to be used in double battles.
It is very questionable....the Aura thing would be its only excuse for learning that, and it's not a very good one.
For the whole Toxic thing, I guess every pokemon (aside from Unown) has some kind of bio-hazard in its body that could be poisonous. It's worth looking into...
Mew learning anything really isn't crazy at all. And IIRC, it canNOT learn Sketch and Chatter, for some reason.
Love Dunsparce though!
I figure that Dunsparce, being a snake, can contort its face to make a glare.
Why WOULDN'T Surf be Water typed? Even if Pikachu is using it, you still need water to surf....it's not unbelievable. Snorlax can do butterfly stroke......
About that bit "in the middle of desert," I have no idea what you're talking about, actually.
According to bulbapedia, the Japanese version of Sucker Punch literally means "surprise attack". Also, a sucker punch doesn't exactly HAVE to be a punch, you know.
....I guess the Spheal line is too heavy to steal effectively