"I am whispering to you, Zuma, wherever you are, those soldiers are going to turn their guns against you," Malema told supporters during a near two-hour speech in which he spoke without pause or a sip of water until his voice started to break.
"Leave office before the soldiers turn against you. The army is EFF."
The EFF was "not afraid" of Zuma, he said.
"Zuma will not be president by 2019... The army is going to take... [up] arms against them [the government]. This army will turn."
Malema said that, while the Economic Freedom Fighters was "the most peaceful organisation," it would "defend" itself.
"We are not provoking violence... We fight in Parliament. We fight in court...
"We will never start any violence. We will never... [point] guns at innocent people. But anyone who comes with violence and thinks that they can intimidate with violence – we will defend ourselves…
"We are not scared of war. Neither are we scared of violence."
He said that it was only because "the ANC is led by clowns" that comments he made to Al Jazeera in a recent interview had been called treasonous.
Malema was also scathing in his reference to State Security Minister David Mahlobo. "You are a small boy… you are an intelligence minister who is not intelligent."
"We said we are going to Parliament to stop the Nkandla corruption, I'm happy to say, we have stopped that. They were undermining the Public Protector's office, I’m happy to say, we have changed that."
He also suggested that the EFF's presence in Parliament had prevented MPs from snoozing.
"They used to sleep in Parliament, but we have woken them up," said Malema.
"Even [President Jacob] Zuma used to sleep in Parliament, but today the old man is always awake because there is no bed of roses for Zuma in Parliament."
Malema said that since gaining its 25 seats, the party was changing Parliament to be more representative of the country's people.
"They [EFF MPs] sound like they are 250, yet they are 25."