The Islamic State (ISIS) has just lost a symbol of its brutality — the terrorist group's behemoth and "scariest" chief executioner who had reportedly beheaded more than 100 people.

His real name is unknown, but he's called Abu Sayyaf, an Arabic name which means "father of swordsmith," the Daily Mail reported. Incidentally, Abu Sayyaf is also the name of the notorious Islamist kidnap for ransom group in the Philippines known for beheading its hostages, which has linked up with ISIS.

How Abu Sayyaf the executioner met his bloody end is not yet clear with news outlets giving conflicting accounts.

Iraqi News, citing security sources who spoke to Alsumaria News, said a group of men ambushed and stabbed him to death.

"The armed group ambushed him at al-Dawasa region, in the western side of the city, and stabbed him several times. He died immediately," Iraqi News quoted the source as saying.

However, ARA News reported that Abu Sayyaf died when a group of armed men opened fire on his car while travelling. "He was killed along with another militant who was accompanying him during the attack," local media activist Abdullah al-Mallah told the news outlet.

Abu Sayyaf had been featured in various ISIS propaganda videos, with his huge, tall and dark frame looming over his victim.

He gained extra notoriety for collecting the heads of his victims and dumping them in a hole in al-Khasafa region, according to the Daily Mail.

At least three other notorious ISIS executioners have also met bloody ends.

In October 2016, a mysterious figure known simply as the "Sniper of Mosul" killed with just one shot an unidentified ISIS executioner who was about to behead a captive Iraqi teenager.

A month earlier, a British Special Air Service (SAS) sniper shot dead an ISIS executioner and three other jihadists, preventing another mass execution of captives with the use of a flamethrower. Posted nearly a mile away from the execution site near Raqqa, Syria, the ace SAS shooter used a Barett .50-caliber rifle to hit the fuel tank strapped on the back of the executioner, triggering an explosion that instantaneously killed him and the three other ISIS militants.

And then there was "Jihadi John," perhaps the most notorious and most wanted ISIS executioner. The English-speaking terrorist who became the first embodiment of ISIS brutality was blasted to smithereens in November 2015 when an armed drone fired a missile that directly hit him while he was about to step into a car in Raqqa.

Identified as Mohammed Emwazi, Jihadi John became a household name for the series of ISIS videos showing him beheading captured U.S. journalists Steven Sotloff and James Foley, aid worker Abdul-Rahman Kassig, British aid workers David Haines and Alan Henning and Japanese journalist Kenji Goto.