Thrash the Devil was a Mobian Tasmanian Devil-one of the few remaining-who set out on a quest to find and punish the Echidnas who mutated and destroyed his people. After briefly joining the Downunda Freedom Fighters, he continued his mission against the Echidnas, coming into conflict with Team Fighters and Knuckles the Echidna in the process.
Thrash was born as one of the last Mobian Tasmanian Devils, a race which had been mutated into Mobini Devil Dogs by Echidna Albion scientists during the Forgotten War. Over many generations their race produced less and less full-blooded Devils to carry on their line, thus leaving Thrash as perhaps the last known Mobian Tasmanian—in fact, his two sisters were born Devil Dogs. At some point in his life Thrash decided to set out on his own quest to find and exact revenge upon the Echidnas with his two sisters, but achieved little, and decided to join the Downunda Freedom Fighters to "bust up a few heads for a good cause." (SSSM: #2, SU: #11, CSE)
Helping DownundaWhile fighting the local Dark Egg Legion, Thrash and the other Downunda Freedom Fighters helped fend off a group of Wing Dingoes attacking the Chaotix as part of an assault to steal the Master Emerald. After the two groups worked out a plan to free the Angel Island, Thrash, Walt Wallabee and Barby Koala took Dr. Finitevus with them in the guise of working together while secretly intending to eliminate the mad doctor. Thrash made the first move, but Finitevus' taunts caused him to lose his temper and gave the doctor an opening to use the Devil to knock out Walt and himself. Finitevus was soon joined by Bill's troops, and Thrash and the others were captured. Once they were released by Bill and learned how he was forced to lead the Legion, Thrash led the counterattack by blasting off the door of the shed they were trapped in with his powerful lungs. After routing their forces and causing the Platypi to retreat, Thrash informed his team that he would be continuing his own quest and then departed via a lone Warp Ring that he had found after the battle. (SU: #11, #12)
Revenge at Last
Thrash's quest had reached an impasse of sorts, but this all changed when he and his devil-dog pack discovered the secret lair of Dr. Finitevus deep in the ruins of the Second Downunda Colony in Sandopolis on Angel Island. Once there, he found notes on the hidden Echidna homeland of Albion and also discovered how to supercharge his warp ring. With this information, Thrash went to Shrine Isle and ambushed Julie-Su and Saffron who were guarding the Master Emerald, and once he charged his ring via the Emerald he trapped both of them in parts unknown. His first Echidna victim successfully sealed away, Thrash and his devil-dogs made their way to Albion where the last Echidna population in the world was under attack by Lien-Da and her Dark Egg Legion chapter. Luckily for him, an accident with the city's electric defense grid had knocked out a majority of the Mobians fighting in the city including Lien-Da, Remington and all of their respective forces, as well as Sonic the Hedgehog and his Team Fighters. Thrash left Sonic and his team alone while using his super-charged Warp Ring to trap the Dark Egg Legion and E.S.T. in the same place he sent Julie-Su and Saffron. Thrash then went to the docks and, posing as help, guided the rest of the remaining Echidnas into another Zone while telling them to "hop on through, and you won't worry about nothin' again. Promise." While Thrash was getting rid of the final echidna, he was discovered by Knuckles and the recently-awakened Team Fighters. After Knuckles explained how he knew Thrash, the Tasmanian Devil explained how he used the Warp Ring he found to trap all of the echidnas, and then quickly was attacked by Knuckles, who Thrash blasted away with a sonic scream. Thrash told Knuckles he would let him live, but was then spin-dashed in the back by Sonic, who demanded that Thrash free the Echidnas. Thrash refused, and he and his pack began battling Sonic, Knuckles, Amy Rose, and Tails for the fate of the Echidnas. (StH: #244)
Thrash quickly became Knuckles' opponent of choice, and the Devil took the opportunity to reveal to the Guardian his reasons for acting against the Echidnas: the crimes that their ancestors had committed in turning the race into Devil Dogs. He rejected Knuckles' assertions of the current Echidnas' innocence by asserting that of his own people when the Echidnas originally tampered with them, and explained that in his mind, he had settled the score. He revealed that his idea of doing so was leaving Knuckles as the last of his race, just as Thrash was; Knuckles quickly dismissed his notion as idiotic, and retorted that the Echidnas might have been able to help the Tasmanian Devils. Convinced that the scientific race would have repeated their crimes eventually, Thrash remained firm in his conviction. After Team Fighters managed to imprison his pack and Knuckles proved too skilled of an opponent for him to overcome through fisticuffs, Thrash employed his sonic howl instead. However, Knuckles fought his way through it, knocking Thrash to the ground with a punch. Just as Team Fighters was about to retrieve his Warp Ring, however, the Krudzu Hybrid Hydra/Metal Knuckles fusion attacked them. Taking advantage of the distraction, Thrash activated his Warp Ring in order to escape, but was pursued by Knuckles.(StH: #245)The pair continued their battle as the Warp Ring deposited them in Downunda near a gathering of Tasmanian Devil ruins. Still fighting ferociously, Knuckles shrugged off Thrash's blows, grabbing his opponent and throwing him through a nearby wall. Thrash landed in a room occupied by two more Devil Dogs with similar coloring to his own and an elderly Tasmanian Devil, who pointed an accusing finger at Knuckles. Thrash quickly recovered and blasted Knuckles with his howl again, before activating his Warp Ring and leading Knuckles on. Their battle continued in the White Acropolis Peaks, where another howl from Thrash set off an avalanche after a brief exchange of blows. Thrash escaped through his Warp Ring again, this time to Shrine Isle, where he promptly threw the ring off the island and jumped through it again to an unknown destination, leaving it to Knuckles, who was unable to use it to reach the Echidnas. (StH: #246)
Thrash is rough, but fair with a strong-albeit warped-sense of justice, as seen by his willingness to let Knuckles live after exiling most of his fellow Echidnas. Unfortunately, he possesses a profound hatred of Echidnas since a rogue group of them turned most of the ancient Tasmanian Devil tribes into mindless dogs, and his people have passed down a tradition of hatred towards the Echidnas with no distinction made between those actually responsible and the rest of the species. In fact, Thrash's sole goal in life is to find and take revenge on the Echidnas who devastated his kind-a goal which he eventually succeeded in. Dr. Finitevus referred to Thrash as a "failed experiment", possibly meaning that to him, a mindless Tasmanian Devil is more useful than an intelligent one.
Thrash is a bit rough around the edges and holds a deep desire for revenge, but usually acts somewhat easy going. He does possess some measure of noble ideals, as shown by his willingness to join the Downunda Freedom Fighters in battling the Legion and his initial kindness to Team Fighters upon finding them unconscious in Albion. However, he has a very short temper-particularly in the face of Finitevus' taunts and jabs at the state of his species-and seems to enjoy fighting. Even more tragically, he fails to recognize that the modern Echidnas were not responsible for the deeds of a handful of their distant ancestors, and makes no effort to distinguish between heroic Echidnas like Knuckles and Julie-Su and villainous ones like Finitevus and Lien-Da. Due to being the sole member of his species, he is an expert survivalist and formidable fighter. (SSSM: #2, SU: #11, CSE, StH: #244)
Thrash is gifted with considerable strength on par with that of Knuckles, able to take on Wing Dingoes with his bare hands. His fighting technique is far from skilled, though, as Barby Koala apparently views his ability in combat as unprofessional, referring to him as a thug. Furthermore, Knuckles was able to defeat him in their initial battles, indicating that Thrash is not as skilled a fighter as Knuckles. He is able to project his voice as a kind of sonic attack, strong enough to break down some objects and send multiple enemies flying. (SU: #11, #12, CSE)
Thrash is a large, purple-furred Mobian with yellow eyes, a furry beige muzzle, and a jagged white-fur pattern on his chest reminiscent of the Guardian birthmark. The fur on his head resembles a cross between Sonic's quills and Knuckles' dreadlocks. His attire consists of green gloves and shoes with metal squares on the gloves and metal bands across the instep of the feet, with circular bumps protruding from them. The gloves and shoes also come with black cuffs, with the gloves' having white lines bisecting the black.
- Writer Ian Flynn revealed on his forum that he created Thrash's concept design off a videogame glitch from the SEGA game "Sonic and Knuckles", which had a character sprite resembling a weird purple hedgehog/echidna mix as the player attempted to switch characters.
- Thrash's "sonic roar" may be in reference to the real-world species' capability to emit extremely loud shrieks and growls.
- Thrash somewhat resembles Bark the Polar Bear, Storm the Albatross and Sonic's Werehog form in terms of overall body shape & design, and displays physical strength similar to all of them. He also shares physique elements with Vector the Crocodile, and his wrist bands/glove cuffs are based on Vector's own.
- In the third issue of the Sonic Universe Graphic Novel Series, Ian Flynn stated that Thrash was meant to be a character who could "throw down with Knuckles and have it mean something" given Knuckles' somewhat limited rogues' gallery. This was somewhat confusing given the character's heroic introduction, but was cleared up with his second appearance and vendetta against the Echidnas.
- It may be considered that Trash was the great responsible for making the Echidnas a species on the brink of extinction in Mobius. The only survivors of his deeds were Knuckles, Dr. Finitevus and Dimitri.
- In real life, Tasmanian Devils are natural predators to Echidnas, hence why Thrash has hatred towards all Echidna kind.