Inspired by this:
I’ve been thinking about a dinosaur origin for Gamma World since seeing that tweet. Dinosaur as a concept is pretty broad, so I decided to focus on abilities to represent a Tyrannosaurus Rex. I could see origins for some other iconic dinosaurs like Triceratops or Stegosaurus, but I felt that T-Rex was the most interesting option.
After a quick brainstorming session, I had a short list of iconic Tyrannosaur traits: big bite, tail, cold-blooded, carnivore, short arms. I knew I wanted the novice attack to be a bite, but I wasn’t originally sure about the other powers. I also decided that cold-blooded cold make a good negative trait, but I didn’t want it to be a standard weakness to cold. I thought that a tail attack could potentially play into the expert attack, but I struggled to come up with anything that seemed right. Working the carnivore theme into the bite attack proved pretty easy, and it also ended up inspiring the utility power. The short arms theme was another tough one because I didn’t want an additional negative trait on top of cold-blooded. After a couple drafts, I’ve ended up with an origin that I think pretty well captures the core themes I was going for, even if I ended up relegating short arms and a tail to the flavor text.
While working on the origin, I knew that it would be a good stand-in for an alligator, but once I had finished, I also realized that it could pretty easily be re-skinned as a sharkoid. The only changes that seemed necessary were in the traits, in order to replace the cold-blooded and defense bonuses with a swim speed and gills. I also switched the associated skill from Nature to Athletics because it seemed like a better fit for a sharkoid.
You can download the Tyrannosaur origin here: http://glimmthegnome.files.wordpress.com/2010/11/tyrannosaur.pdf
Or, if you prefer, you can download the Sharkoid version here: http://glimmthegnome.files.wordpress.com/2010/11/sharkoid.pdf