Pinkie Pie seems to be associated with breaking the 4th wall, but there seems to be other people doing that(like Ed, Edd n Eddy).
This picture is based on the very first 4th wall moment I've ever seen: [link]
Note: I'm still neutral to MLP. I always seem to draw them human, maybe it's because I'm more comfortable about that.
MLP belongs to Hasbro.
Mario belongs to Nintendo.