In a new terror video posted online he vows to 'achieve a victory for Islam' using the huge blade, which is inscribed with an Arabic passage from the Quran.
In pictures designed to scare British and American soldiers is also seen sitting with an AK47 rifle.
Terrorism expert and author Chris Dobson told The Sun: ‘The bloodthirsty threat of Abu Askar the German and his giant cleaver is plain - anyone who opposes us will lose their heads.
‘Fanatical Islamic Jihadists have a record of beheading captives and boasting about it to cause fear among their enemies.
‘Abu Askar and his knife are undoubtedly part of the “war of the mind” the Jihadists are waging against the West.
To see the picture go to Mail Online