I really love Muk. I was thrilled to find out you could get Muk with HA in the hidden grottos in BW2 since Muk's other abilities are kinda meh. In a stroke of luck, I wound up finding a Muk in one of my early attempts at visiting hidden grottos but alas, it was male, meaning I can't breed for the right nature/egg moves. Because gender is not SR, I now got a sad male Muk with HA in my box.
So I'm looking for a female Grimmer or Muk with HA. I got a couple females with HA that I could breed for you in exchange, such as:
If none of these interests you, I also have two males with HA (Muk and Gothorita) that I also wish to part with and would be glad to trade away. Otherwise I don't have any legendaries to offer, but I have a bunch of multiple pokémon to help improve your dex (particularly from gen 3, 4 and all of 5) and would be willing to trade multiples for her.