Cleve is a minor antagonist of Dragons: Race to the Edge and one of the too main antagonists (alongside Ingar Ingerman) from the episode, Loyal Order of Ingerman.
Cleve is the leader of the Dragon Hunters of Dramillion Island. When Fishlegs and Astrid went to that island, Fishlegs told Cleve to stop his evil-doing, since Fishlegs is a direct descendant of Ingar Ingerman, who is a dragon hunter with hunting legacy, but Cleve refused to stop. Fishlegs freed all Dramillions and destroy the statue of Ingar Ingerman.
Cleve has same appearance with other dragon hunters. He is also buff and has mohawk-like helmet. One difference is he wears a red vest, because he is the leader.
Cleve is likely to be xenophobic to dragons and this is probably why he and his men abused Dramillions. He also wanted to follow the legacy of Ingar Ingerman.