Ulysses Klaue was the son of Nazi war criminal Colonel Fritz Klaue. After World War II he moved back to Belgium and later anglicized his name to "Klaw," and raised his son with tales of Wakanda.
In adulthood, Ulysses became a physicist working in the field of applied sonics at the Technical University at Delft. He designed a sound transducer able to convert sound waves into physical mass, but the theoretical element necessary to make his device work was Vibranium, a substance known to exist only in certain meteoric deposits in the small African nation of Wakanda. Desperate for a sample, Klaw organized a group of mercenaries to help him seize the element from the Wakandans, and bought intel on how to access Wakanda from Hydra.
After the Wakandan king and bearer of the royal mantle of the Black Panther, T'Chaka, refused to yield any of the metal from the sacred mound, Klaw and his mercenaries opened fire. When Klaw's sonic weapons overpowered T'Chaka, the young prince T'Challa ran to his father's aid. Klaw prepared to kill T'Challa, but T'Chaka shielded the boy with his body, and lost his life. Klaw was disarmed by Wakandan warrior Zuri, who pierced Ulysses' right arm with a spear, and the orphan prince used Klaw's own sonic blaster to shatter his right hand, prompting him to call his troops to retreat.
Ten years later, he mounted a second attack on the Wakandans. He was opposed by the Fantastic Four and T'Challa, now the Black Panther, who had succeeded his father as ruler. Thwarted again, Klaw leaped into his massive sonic converter device (the Vibranium for which he had acquired criminally on the open market), hoping to gain superhuman powers to combat his foes. His gamble was successful and Klaw was transformed into a creature whose body was composed of "living sound". In his new form, Klaw battled the Fantastic Four and was pummeled into unconsciousness by Mister Fantastic, wearing Vibranium knuckle guards, and was taken to prison.
Klaw was soon freed by the Crimson Cowl, an alias of Ultron, and invited to join the second Masters of Evil. The Masters of Evil managed to capture the Avengers, but they later escaped. Klaw was subdued by a kick from his old foe, the Black Panther. Too powerful to be imprisoned by conventional means, Klaw escaped and freed some of his cronies from the Masters of Evil. A second foray against the Avengers was less successful than the first and Klaw was again subdued.
Managing to escape custody again, Klaw journey back to Wakanda where he helped steal a device capable of augmenting the metal-disintegrating property of a Vibranium-alloy. Encountering the Thing, the Human Torch, and the Black Panther, Klaw was defeated when the Thing crushed his prosthetic hand.
After rebuilding the device, Klaw joined forces with the murderous Solarr and trapped the Avengers within a solid sound barrier. Klaw threatened to execute the Avengers if the Black Panther did not abdicate the throne of Wakanda to him. The Panther managed to subdue Klaw and Solarr before he could make good his threat.
Klaw was later freed from prison by a member of the extra dimensional race of Sheenarians, who wished him to use his sonic powers to help open a dimensional portal big enough for their invading armada to enter Earth. Klaw agreed and after a skirmish with Ka-Zar in London, traveled with the Sheenarian to the Savage Land where there was a Vibranium deposit large enough to create the portal. Klaw and the invaders were defeated and Ka-Zar forced Klaw to open a portal to their home dimension. Klaw managed to escape from Ka-Zar and remained in the Quarl dimension with the Sheenarians. Unable to salvage anything substantial from his allies, he used their technology to return to Earth.
Materializing in the Nexus of All Realities located in the Florida Everglades, Klaw happened upon the wand of the Molecule Man. Helping the Molecule Man find a body to possess, Klaw and his new ally traveled to New York to wreak revenge on their common enemy, the Fantastic Four. Klaw was subdued by the visiting Impossible Man. He later teamed up with the Mad Thinker to battle the Vision and the Fantastic Four.
Klaw began to realize that his sonic powers had been waning over the years and undertook an elaborate scheme to manipulate a youth gang into restoring him to full power. Klaw had the local Thunderbolts Gang accost him and take his powerful Sonic Horn. The Black Panther tried to stop the threat but a gang member used the horn to blast him. The Panther retrieved the comatose Klaw and took him to Avengers Mansion and stored him with his team mates in a protective stasis. The Panther then pursued the gang but they used the sonic weapon to create a creature of sound, a winged elephant with deadly claws. Captain America and Black Panther managed to defeat the winged elephant sound construct and rushed to the docks fearing Klaw had a plan to escape his suspended state. At the docks Beast and Vision are attempted to ship Klaw's body to Wakanda when the Thunderbolts show up with Klaw's sonic-horn. They made a construct of a rhino and lion to keep the Avengers at bay while they blast Klaw with his horn to revive him. Revived and stronger than ever Klaw battled Vision behind a sound dome the other Avengers couldn't penetrate. Suddenly N'Yaga and Taku showed up in a limo with the Panther's vibranium claws which dampen sound waves and would allow him to fight Klaw one on one. Black Panther ripped through the dome, and finding Vision defeated, attacked Klaw. The dock was blasted in the melee, dropping Klaw and Black Panther underwater. The Panther managed to blast Klaw with his own horn, causing his body to dissipate.
Klaw's prosthetic device was recovered and taken to Project P.E.G.A.S.U.S., a government energy research facility, for analysis and safekeeping. When Solarr, another ward of the Project, was inadvertently freed from his containment cell, he sought an ally to help him escape from the heavily-fortified facility. Finding Klaw's hand-blaster, Solarr thought that the Project was responsible for killing him and threw the device angrily against the wall. The sonic vibrations of the impact provided the necessary energy for Klaw, whose mental essence had found refuge inside the prosthetic device, to reconstitute his solid sound body. The two criminals' attempt to escape was thwarted, however, and Klaw collapsed back into his sonic device. Project scientists soon revived him again in order to study him. Weeks later, when the mutant Dazzler was at Project P.E.G.A.S.U.S. to have her sound-transducing powers tested, Klaw tricked the mutant into helping him escape confinement. Realizing her mistake, the Dazzler used her body's sound absorbing abilities to siphon Klaw's energies totally into herself. Klaw's mental essence, rendered unconscious, was also transferred to the Dazzler. When the Dazzler expended the vast quantity of energy that is Klaw while aboard the starship of the world devourer Galactus, the advanced alien circuitry of Galactus' craft absorbed it and Klaw's mental essence.
Some time later, Galactus was among the many beings assembled for study by the omnipotent extra dimensional Beyonder. Needing to consume the energy of a planet-sized object, Galactus sent for his solar system sized home base, docked to which was his starship. Doctor Doom, another of the beings abducted by the Beyonder, stole aboard Galactus' home base to find weaponry to battle first Galactus then the Beyonder. While trying to fathom the alien technology, Doom used Galactus' machines to bodily resurrect Klaw, whose mental essence had been flitting through the circuitry of the base. As a result of his experience in disembodied form, Klaw was mildly insane when Doom restored his form. Doom nevertheless exploited the fact that Klaw's energy-form was attuned to Galactus' ship and carved up Klaw's non-organic body into special lenses. These lenses enabled Doom to siphon the energy released when Galactus converted his home base into fuel succeeding in the audacious scheme, Doom attacked the Beyonder and the Beyonder gave up his power to Doom in order to see what Doom would do with it. Doom believed he had totally eradicated the Beyonder from existence, but the Beyonder instead took refuge inside Klaw's now restored energy form. After witnessing how Doom handled his omnipotent power, the Beyonder manipulated Doom into returning it. The Beyonder then dispatched Doom and Klaw back to Earth. Klaw then appeared to be restored to his previous power levels and appeared cured of his insanity.
The Wizard assembled a new Frightful Four; along with Klaw, Hydro-Man and Titania. They attacked the Four Freedoms Plaza and during the fight the Thing was thrown into device and transformed from his rocky appearance to normal human form. The Fantastic Four, without the help of Ben, battled the new Frightful Four and managed to beat them into retreat. Reed repaired the computer system, which was compromised by the Wizard, and located their hideout. The Fantastic Four arrived at the warehouse and launched their attack on the Frightful Four, but were immediately disabled by Aron, an unknown ally of the Wizard. The Wizard argued with Aron about what to do with the Fantastic Four. Aron revealed that he merely wanted to collect tissue samples from Johnny Storm to further his yet unknown plan. Aron and Dragon Man, now under the control of Aron, left, and the Wizard decided to imprison the Fantastic Four to torture them. Ben snuck in to the Frightful Four's headquarters and freed his friends. A battle ensued and the Fantastic Four emerged victorious. As the heroes lead the villains away in restraints, both teams were transported away only to find themselves face to face with Aron and a set of Fantastic Four doppelgangers.
Klaw was one of the many criminals kept in the Vault. He and the other inmates escaped but were stopped by Iron Man and Hawkeye. He later attempted another breakout with a group of other inmates. He and various other criminals witnessed Captain America disguised as Crossbones battle Batroc.
He joined the Pacific Overlords a group of super-powered individuals who gained their powers through experiments and procedures conducted under the watchful eye of the once-brilliant geneticist turned criminal subversive, Doctor Demonicus. Principle among Demonicus's procedures was exposure to the few remaining shards of the highly radioactive meteor called the Lifestone. Demonicus eventually came under the control of a demon and used the Overlords to advance the demon's message. Kuroko requested help from the Avengers West Coast. The nation of Demonica and the Overlords apparently sank beneath the Pacific Ocean.
When Johnny Storm went to trial for setting fire to Empire State University, he was attacked in the courtroom by Paibok and Devos. Simultaneously, Klaw attempted to have his revenge upon the Fantastic Four by manipulating Huntara into joining them. Working together they attacked the FF as the Fearsome Foursome. However the Fantastic Four were joined by Spider-Man, Sandman, Silver Sable and Daredevil. They were winning until the Avengers arrived. They decided to retreat through a portal opened by Huntara. Daredevil attempted to pursue, but the dimension in which he found himself confused his senses, and he had to be pulled out by Spider-Man. On Paibok's starship they planned to destroy the FF at Four Freedoms Plaza, where they lay in wait for the Fantastic Four's return. When the heroes returned, Huntara launched into battle with Psi-Lord, leading the two of them away from the others. The remaining members of the Fantastic Four were taken out by knock-out gas delivered by Devos and Paibok. The two allies then teleported their captives to Paibok's ship, so that they could turn them over to the Skrull Empire. After they had disappeared, Klaw came out of hiding, and took the unconscious body of Ms. Marvel (Sharon Ventura) prisoner.
Klaw was among the villains assembled by the newest Crimson Cowl in the newest incarnation of the Masters of Evil, only to be ultimately defeated by the Thunderbolts.
He joined the Intelligencia and helped the team to find Ultron, who returned Earth. At some point later, he battled Thor, and Iron Man, although he was able to create constructs of himself, he was defeated and imprisoned by Mr. Fantastic in a special containment unit. One of his constructs (also called echoes), managed to avoid the heroes and tried to become a new Klaw using more echoes, who were on the loose, and using Daredevil as a new body. Daredevil managed to escape the echo's hideout. While battling it, the construct along the rest of them were disintegrated.
During The Wizard's attempt to reinstate the Frightful Four Klaw saved him from their newest member's attack on The Wizard. The villains later transferred the Carnage symbiote to Karlin Malus, who was mind-controlled by The Wizard to prevent him from going rogue.
Along with a new "superior" Carnage, the villains attacked City Hall in order to take over New York, but they found themselves against Spider-Man. During the battle, The Wizard lost control over Carnage, and Malus went rogue. Using a vibranium blade he found in The Wizard's hideout, Carnage stabbed Klaw in revenge. The disruption of Klaw's sonic body caused by the Vibranium made the villain explode, seemingly killing Malus and taking the symbiote from him in the process.
However, Klaw didn't die. His body was dispersed along with his consciousness. Using his remaining energy, Klaw managed to redirect a lightning to Cletus Kasady, who had re-merged with the Carnage symbiote, and basically saved the day. Klaw stated that his consciousness would continue to disperse throughout the sound wall to the point it would disappear. However, he has reappeared reconstituted again after these events.
