Damon Smith, 19, appeared at Westminster Magistrates Court in London over the incident on October 20 which sparked a security alert.
He entered no plea to a charge of unlawfully and maliciously making or possessing an unspecified explosive substance with an intent to endanger life or cause serious injury to property.
IS-inspired London Tube knifeman jailed for life
But his lawyer indicated that Smith, who has a form of autism, would at a later date plead not guilty on the grounds that it was a prank.
Two members of the public discovered a backpack on a Jubilee Line train.
It was handed to the driver, who found it contained a suspicious device, prompting the evacuation of North Greenwich station.
A controlled explosion was carried out on the device, which comprised a flask, powder, ball bearings, a clock timing device, a battery and an initiator.
Smith smiled throughout the 18-minute hearing Thursday.
He was remanded in custody and will next appear at the Old Bailey in London, England's central criminal court, on November 17.
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