Wikipedia
After the emperor Nero committed suicide near the villa of his freedman Phaon in June of 68 AD, various Nero impostors appeared between the autumn of 69 AD and the reign of the emperor Domitian. Most scholars set the number of Nero impostors to two or three, although St. Augustine wrote of the popularity of the belief that Nero would return in his day, known as the Nero Redivivus legend. In addition to the three documented Pseudo-Neros, Suetonius refers to imperial edicts forged in the dead Nero's name that encouraged his followers and promised his imminent return to avenge himself on his enemies.
Belief in Nero's survival may be attributed in part to the obscure location of his death, although, according to Suetonius, Galba's freedman Icelus saw the dead emperor's body and reported back to his master. Nero was also denied the lavish burial that was accorded to popular emperors and members of the imperial family, which may have left those plebeians who loved him dissatisfied and suspicious. Furthermore, he was not buried in the Mausoleum of Augustus with the other Julio-Claudian emperors, but in a tomb on the Pincian Hill at the family burial place of the Domitii Ahenobarbi. The postmortem popularity of Nero among the Roman plebeians inspired them to lay flowers at his tomb.
Another possible source of inspiration for those who impersonated Nero was the circulation of prophecies that predicted he would regain his kingdom in the East. One version placed his resurgence at Jerusalem. These prophecies have been tied to Nero's natal chart, which has been interpreted as pointing to a loss of his patrimony and its recovery in the East. Tacitus may have been referring to such prophecies in veiled language when he wrote of the rumors that circulated about Nero after his death, which had contributed to the belief that he had survived. The return of Nero may have inspired the author of the Book of Revelation when he wrote about the eschatological opponent called the Beast, which is mortally wounded and then miraculously heals. The number of the Beast, 666 or 616, depending on the manuscript, has been identified by some as the numerical value of the letters in Nero's name. Nero also appears more explicitly in this role in the Ascension of Isaiah and some of the books of the Sibylline Oracles. Owing to these prophecies and others, Nero was long thought to be the Antichrist.
Due to the short-lived success of the Nero impostors and Nero's incorporation into eschatological literature, the belief in Nero's imminent return lasted for centuries. Lion Feuchtwanger wrote a historical novel based on the second known Pseudo-Nero, Terentius Maximus, entitled Der falsche Nero. This novel was published in 1936.