#4. Luchasaurus
Just like Kiss, Luchasaurus appeared in Lucha Underground in its later years. He first appeared as the "end boss" of the Reptile Tribe led by Kobra Moon and was known as Vibora. His unfortunate end came when Johnny Mundo, who was cosplaying as Indiana Jones, infiltrated the tribe's lair and cut off his head, which was done to write him off of the show.
But what he did show in the promotion was that he was a special performer. He was agile, quick and a stiff striker. Since he towered over a good deal of the roster, they often played up his size advantage over most of his opponents. The crowd routinely chanted "Luchasaurus" when he was in the ring because of how impressive he was in such a short amount of time.
He also had a few matches in Ring of Honor and continued to impress people with his skill. A fun fact is that he and Jungle Boy have trained together and have been friends for more than 10 years. I originally just thought it was a gimmick, but there is some history to the pairing. If AEW books him right, he will be one of the many crowd favourites right away.