I found this fairly recent
Cracked article and it mentions the creation of both the Predator's design and the designs for the Dogalien and Newborn.
Also it mentions the Green Goblin, Prauns and Jabba the Hutt, if you don't already have a reason to click on the link.
The most amusing thing about it, to me, was the .gif of the dog they dressed up in a Xenomorph costume.