In the (Special Features) menu, go to (Cut-Scenes). Move [Down] to (Evil Council's Love Tacos) and press [Right]. A silhouette of a man appears to the right. Select the man, and press [Enter].
From the disc's (Main Menu), select (Special Features). Once you get to that menu, by default (Behind the Scenes Featurette) will be highlighted. Press the [Up] arrow key on your remote control three times and the silhouette of the "Matrix Cow" will appear on the screen. Press [Enter] now and you will see a slow motion reenactment of the cow nipple-thumping scene.