As of 3/16/2012 10:35AM MT (I'm going to update here only from now on):
I think it's safe to conclude that these are only for the base set, since none of the chase cards have appeared...
Bat (2)
Behead
Brains-burgers
Chafeguard
Charredstone Chew (3)
Cling Freak (2)
Grave Poupon (3)
Hippy Days
Homely Comb (2)
Olden Grahams (3)
Preparation H-Bomb
Tiger Eat
Town Hovel