I don’t know if this is the drone sub that was previously reported or if it is the drone sub that carries this torpedo but the drone aspect means the following:
1. It’s ability to stay underwater indefinitely is alarming.
2. Because something will go wrong while its waiting and nobody is on board to fix it.
Those drone cars have their share of bugs.
On the diagram the giant torpedo's range is given as "up to 10,000km" (6,200 miles) and depth of trajectory is "up to 1,000m" (3,300ft).
It was developed by Rubin, a submarine design bureau in St Petersburg.
It would, apparently, be launched by nuclear-powered submarines of the 09852 "Belgorod" and 09851 "Khabarovsk" series.
Rossiiskaya Gazeta called the torpedo a "robotic mini-submarine", travelling at 100 knots (185km/h; 115mph), which would "avoid all acoustic tracking devices and other traps".
Something with that kind of performance would require nuclear propulsion too!