also I'm not sure but I think the reason most people voted Quetzalcoatalus was because they are thinking of Quetzalcoatl which looks way more bad ass. (probably they didn't even bother to click the link to see) I know I did because I was thinking of a Quetzalcoatl as well but I noticed it was spelled funny, than I clicked the link and saw that it was actually a real creature and not an awesome feathered dragon worshiped by the Aztecs *sad face*
The Quetzalcoatalus was named after the Aztec god of the similar name. It was actually a pterosaur taller then a giraffe. It would eat baby t-rex... which makes it a pretty badass creature if you ask me.