Linhenykus: the thing that makes this one so odd is its teeny tiny forelimbs. Not only are they small, but they only have a single finger on each one. I decided that they were small enough to go unnoticed under a puffy layer of feathers. We always make fun of T-rex for the size of its arms, but linhenykus takes the cake… well, he would if he had bigger arms… and more fingers. And only if it was a fairly small cake because he is a pretty small dinosaur, coming up to about your knee, depending on what posture it stood with.
I am very thankful to Kory Bing for composing such a wonderful list of very strange dinosaurs.