Here is a Jurassic Park themed cake that I made for my cousin. It has a broken reptile egg on top, a glowing T-Rex eye camouflaged by green leaves, and vicious claws coming out of the side of the cake. I kind of love how this one came out.
Sorry I didn't take any pictures during the assembly, but I do have closeups of the different sections.
Here is the egg. I used a chocolate mold but filled it with fondant instead of chocolate. After the fondant had hardened slightly, I used a craft knife to cut it apart and make it look like broken egg pieces.
Here is the glowing eye. I painted the eye with food gel color mixed with piping gel. The gel gives it that wet, slimy look.
And the claws. I wanted to have blood dripping from the claws, but I thought that would be too unsettling for the birthday boy.