Deathroy has the appearance of a frog-like tiny creature, probably no bigger than 3 inches. His lower half is concealed by machinery, although this is actually merely used as a tether to Nene's shoulder. When released, Deathroy takes full appearance of a Frog.
In the story, Deathroy has no real role until the end. He is mainly a simple sidekick to Nene, although he does not support him in battle. At the end, however, when Nene was killed by Zola and the collar of light was used, Deathroy tells his true story and origins, and, having swallowed Nene's light sphere, enters his true form: Destroy. He seems to liquefy like a caterpillar in a cocoon with Szabo in the center. He says in a deeper voice how he feels his power returning.
Once Destroy has fully formed a scene will occur, showing flashbacks of murals in areas like Pachess Town, Mural Town and the Talta ancient ruins. He says he was the most powerful biological weapon ever created, and the boss battle that ensues after proves this to be correct. He has incredible attacks, such as Final Judgment, which involves a massive thunder attack. Oddly, he seems to do less damage than Nene with the eternal engine, although he has a larger array of attacks.
Deathroy's role is the same in the anime except for the Destroy part. Following Nene's destruction, it is revealed that he is the actual owner of Chimera and Nene just manipulates it with Deathroy granting Chimera to whomever as he cannot summon him by himself. Zola abducted Deathroy without anyone noticing and hid him in the Sealed Grounds. He was rescued by Delphinium and by using her artificial shadow Chimera becomes hers to manipulate with Deathroy, while still having her beetle/hydra shadow. Deathroy and Delphinium join in the final battle, with Chimera sealed after Zola in demon form is defeated.
Tenkai no Shichi RyuuEdit
Two years later, Deathroy is still riding on Delphinium's shoulder and she captures Bouquet so that Noi can reawaken Chimera. When it came to fight with Hildegard, Deathroy directly uses his power to save Delphinium. He and Delphinium later help out in the final battle with Rudolph.