I didn't know these cakes were a thing until I saw the facebook stuff going around about awful easter lamb cakes. They look like lambs wearing gimp suits. Now, you can have one too!
As with most things in SD, you can just go with the baseline, or make completely unrelated stupid shit from it.
Usage:
l4mb, frosting, fake grass, jelly beans
If you really want super ugly cakes, go with:
horror \(theme\), ugly