This How to Train Your Dragon Toothless cosplay is amazing! The costume was created by cosplayer Monoyasha, who, as you can see, put a lot of time, effort, and detail into this thing. Here's a note from the creator:
NOT FOR SALE; this video is so people have a chance to see the toothless quad suit up close and personal, so see all of the functions. There is only ONE person inside of this costume. Afterwards I was mauled by children who happened to see me.
Here's the video: