The Islamic State's chief executioner who carried out the beheadings over 100 people throughout his gruesome career in jihad has become the hunted.
Mostly known by his nom-de-guerre Abu Sayyaf, the IS executioner was reported dead on Sunday after he was attacked by a group of unknown men in their Iraqi stronghold of Mosul.
"He was found dead in the Dawassah District, west of Mosul city, in Nineveh Governorate on Sunday evening," local media activist Abdullah al-Mallah told the Kurdish news outlet ARA News.
Sayyaf was known for having a wide-body, large frame and daunting figure, especially when he stood overtop of his kneeling victims preparing to sever their heads off with a machete.
"Abu Sayyaf was one of the scariest executioners in Nineveh," Iraqi journalist Muhammad Yawar told ARA News. "He was known for his huge body and heavy arms. He was one of the renowned faces in the ISIS propaganda videos."
"Abu Sayyaf was a reflection of the brutality of this terrorist group," Yawar added.
Al-Mallah explained that IS' Hisba police force was not able capture or identify the assailants involved in Sayyaf's murder.
It is not immediately clear how Sayyaf was murdered, as there are conflicting reports that suggest two different causes of death.
Iraqi News reports that Sayyaf, who used to dump all of the decapitated heads of his victims in the same pit in the al-Khasafa region, was stabbed to death.
"An unknown armed group killed on Sunday the Islamic State's most famous decapitator, the so-nicknamed 'Abu Sayyaf,'" Iraqi News quoted an unnamed security source as telling the Iraqi satellite media outlet Alsumaria. "The armed group ambushed him at al-Dawasa region, in the western side of the city, and stabbed him several times. He died immediately."
However, the ARA News report suggests that Sayyaf was shot to death by gunmen.
The discovery of Sayyaf's body comes just two days after another known IS executioner was killed.
Abu Abdel Rahman, an IS commander from Saudi Arabia who is known for carrying out the capital punishment of women accused of breaking IS' strict version of Sharia law in Mosul, was shot and killed last Friday.
"The unknown gunmen shot at Abu Abdel Rahman, ISIL's senior commander, in al-Askari region in the centre of Mosul city and he was killed right on the spot," The British news site The Sun quotes a security source as telling the Iranian Fars News Agency.
Sayyaf and Rahman join other prominent IS executioners who have been killed or captured. Arguably IS' most famous executioner, "Jihadi John," whose real name is Mohammed Emwazi, was believed to have been killed in a United States airstrike in November 2015.
In 2016, video emerged showing Syrian troops capturing an IS executioner known as "The Bulldozer of Fallujah" and hauling him away in a pickup truck. It is unclear whether or not the Syrian troops ended up killing the "Bulldozer of Fallujah."
As the Iraqi-led coalition continues its liberation effort of Mosul, IS militants have largely been pushed out of the eastern part of the city. However, the group still holds some ground in the western region of Iraq's second largest town.
"The majority of ISIL commanders have been killed in the Eastern side," Lt. Gen. Abdul Ghani al-Assadi told The Sun.