I've wanted to try this one for years (probably since I first saw the diagrams some years ago), and only now have realized this dream.
This is the Spinosaurus, designed by Shuki Kato. Almost a decade ago (wow) the staff of Origami Weekly produced hand-drawn diagrams for it:
https://www.flickr.com/photos/origamiweekly/4079269103
The download no longer works, but I had a printed copy floating around my house which I used.
Starting with an 18 inch square, some waterbomb like folds yield a structure that little resembles a dinosaur
I have to admit that when I originally got to this part I had also noticed that my paper was not a square, and considered giving up, worried that my references would be too far off the mark for me to be able to complete the fold. Luckily, I persevered.
That picture on the bottom right is me folding during lunch, not at home.
And at last, after some hours worth of total folding, the finished product!
I like the detailed toes and fingers, but I do kind of feel like the forelegs are too short. But otherwise this is definitely a cool design. It also stands on its own!
Here's a quick comparison with the Carnotaurus from last week:
A poorly taken outside picture,
And of course, battle time!
