Ok folks, you asked for it. Here's my NSFW, totally scientifically sound hypothesis. Please be 18 or something. Also, feel free to read this in David Attenborough's voice for better effect. I guess Kenneth Branagh's voice is ok too. Let's get into it. This is Hypnovenator- the sleep hunter. At only 1 m long, it is an opportunistic omnivore that feeds mostly on small animals. This male's bold coloration and eye catching tail fan evolved originally to court females. He is a talented dancer.

Friendly reminder that there's an ancient Egyptian "Tale of the Shipwrecked Sailor", in which a guy gets stranded in an island & meets a giant dragon/serpent-like creature that tells him there used to be more like him, but they all burned to death when a star fell from the sky! The serpent is said to have been 30 cubits long (which I believe equals to about 15 m), with a "beard" over 2 cubits, and eyebrows of lapislazuli, as well as skin inlaid with gold. It was so big it would splinter trees and make the earth shake as it moved through the island!