The killer's size, his large frame and his utter brutality have led some international media such as The Mirror and International Business Times to speculate he is none other than 'The Bulldozer of Fallujah'.
'The Bulldozer' is known for carrying out his brutal punishments with a massive sword, however this killer is instead pictured with a large knife which he uses to kill his victims.
Little is known about his identity, however according to The Sun, citing Iraqi news reports, the killer is an Iranian national.
BRUTAL BEHEADING
In the latest video released this week by Wilayat Nineveh, the Islamic State's press, the killer is seen behind three men who are dressed in orange jumpsuits.
It is not known exactly where the video was shot but it is believed to have been filmed somewhere in Ninebeh Province, Iraq.
In the six-minute video, the three who are Kurdish Peshmerga soldiers, have their throats slit before they are beheaded and their bodies left on the street.
The heads are then placed on the victims' backs.
The killer also threatens to renew attacks inside the KRG who he warns "will be unable to hold off the Islamic State."
The video comes at a time as Peshmerga forces join with both the US and Iraqi army to take back the Islamic State controlled city of Mosul.
THE ATROCITIES
'The Bulldozer' earned a fearsome reputation for the size of the weapons he uses to punish his victims.
In some photos and footage, he is even seen brandishing a machine gun which is said to weigh more than 50kg.
He shows no mercy and has even been known to cut the limbs off children.
Last October, a young boy known as Omar revealed to Britain's Channel 4 how he lost a hand and foot after he refused to join Islamic State.
The teen, whose name has been changed, told the broadcaster he has "given up on life" after 'The Bulldozer' took his hand and foot.
Omar was in Syria fighting with the Free Syrian Army and was running ammunition and food to fighters when Islamic State moved in on Deir Ezzor province.
The young teen was soon captured and transferred to the Mosul and offered a chance at freedom if he joined IS. But he refused and was tortured for six weeks before the grim act which changed his life.
"They gathered the people, they tied down my hand and my leg, they put my hand on a wooden block and cut it off with a butcher's knife," Omar told Channel 4.
"Then they cut off my foot and put them both in front of me for me to see."
JIHAD JOHN
Like 'The Bulldozer', the man who was known as Jihad John always wore a mask when carrying out his horrific atrocities, fearful of revealing his true identity.
The British born militant became the poster boy for Islamic State and was seen in several propaganda videos.
Jihad John, who beheaded several western hostages in 2014, was later named as Mohammed Emwazi.
The executioner who joined IS after becoming radicalised and escaping to Syria was killed in an air strike last November.
In its online magazine Dabiq, the group said Emwazi was killed on November 12 "as the car he was in was targeted in a strike by an unmanned drone in the city of Raqqa, destroying the car and killing him instantly".
- News.com.au
