Shekau, who has been dubbed a "global terrorist" by the U.S and twice been declared killed by the Nigerian military, claimed responsibility for a December 20 attack on a tank battalion barracks in Bama, Borno State.
"Brothers pulverised 21 armoured tanks. People were killed in their multitudes, bodies scattered all over," he said, adding that his forces "blew out the brains" of soldiers who tried to hide under their blankets.
"Had Allah allowed us to eat them we would have eaten them but we are not cannibals," he added, according to reports. "This is a victory from Allah."
The video showed the terrorist leader seated on a mat surrounded by masked fighters. It included footage ostensibly filmed of the attack, with burning buildings and fighter jets and armed, masked men walking around them.
The insurgents stormed the barracks by arriving in a convoy of trucks shortly before sunrise, opening fire on soldiers inside before torching the compound. Witnesses said they kidnapped soldiers along with women and children.
The military has not yet released a death toll from the attack but said that more than 50 insurgents were killed when ground forces backed by fighter jets pursued them after the raid. Locals claimed they also killed an unknown number of civilians and destroyed four villages.
Shekau threatened more mayhem in the video sent to AFP on Saturday whose authenticity has not been verified, although it is one in a series sent to the news agency in which he features.
"As for killing, we will kill because Allah says we should decapitate, we should amputate limbs, we should mutilate," he said.
He also shrugged off the bounties put on his head – $7 million by the U.S and $312,500 by the Nigerian government. "We do not worship money," he says. "You can't in any way harm me."
Jesus help us... This is plain cruelty