Bradley Lowery's parents have been "overwhelmed" after his battle with cancer inspired support from across the world, say campaigners.
The five-year-old, from Blackhall Colliery, touched the world of football after being Sunderland's mascot for their match against Chelsea on Wednesday night.
A fundraising appeal raising more than £700,000 towards treatment in the US, but his neuroblastoma has been confirmed by doctors as terminal.
Bradley's mother Gemma said last week that further treatment will only prolong his life, despite a brief period of respite from the illness last year.
The youngster, whose cancer battle began in 2013, has been swamped with more than 40,000 Christmas cards from well-wishers sending their love from as away as South Korea, charity group Red Dreams said.
Lynn Murphy, the campaign manager for Bradley with Red Dreams, said his parents Carl and Gemma have been taken aback by the extent of public reaction.
"We're inundated, inundated with presents. Bradley's got his own sorting line in the post office in Hartlepool because of the amount of presents."
Ms Murphy said despite Bradley's severe illness he is always cheerful.
"He's a cheeky chappy. He's always got a smile on his face, it doesn't matter how much pain he's in, and obviously the family's been overwhelmed by the amount of support they have had," she added.
Ian McManus, who runs Red Dreams with his wife Dawn, said Bradley was his mother's "little super hero, because he's always smiling through everything he's gone through".
Mr McManus has now produced a charity single with sisters Olivia Crawford, 15, and Georgia Fletcher, 22, in aid of the Bradley Lowery Foundation, which the family hope to set up in support of other sick children in the North East of England next year.
Mr McManus said the song was also about Bradley's legacy: "All we tried to do with the song is give them some memories that they can cherish."
Bradley is expected to undergo another round of chemotherapy in 2017.