Their comments came after parents in Southern California claimed their baby had won that designation, KPIX-TV, San Francisco, reported.
"Fifteen from LA, they said was a record," Sammisano's father, Pava Otuhiva, said in reference to previous reports of record births. "We're just setting the record straight [about] who carries the title ... Sammisano!"
Sammisano was born in August and was the biggest baby on record in California, weighing in at just under 16 pounds, 2 ounces, WPIX-TV said.
"I kind of turned my head to the scale. ... I was shocked," said Sosefina Tagalu, the baby's mother.
Sammisano is 5 months old now, but wearing diapers for children three times his age. He began eating cereal at 3 months old, and his two brothers call him a superhero.
"Twenty-four inches and a half ... that's 2 feet of baby already," Tagalu said.