The little penguin weighs a hefty 1520g.
The average weight for a chick that age is 1200g.
Trust marketing manager Sophie Barker said it was "wonderful" wildlife was thriving at Pilots Beach as the rest of the world seemed to grind to a halt as a result of the Covid-19 outbreak.
Blue Penguins Pukekura scientist Hiltrun Ratz discovered the big chick when she fed and weighed chicks whose parents were moulting, Ms Barker said.
How it got so big was a mystery.
Previously, another chick of a similar size had been "mobbing" other adult penguins for food, she said.
"You never know what goes on during the night at Pukekura."
As of mid-March, 350 chicks had fledged and 62 chicks in the colony at Pilots Beach, and
569 micro-chipped adults had been recorded for the 2019 season.
Ms Barker said the Covid-19 outbreak’s impact had been a "shock" to the visitor attraction.
About 80% of the people who took the Blue Penguins Pukekura tour were international tourists.
Funds generated helped the trust to look after the land at Pilots Beach and to care for the penguins, flora and fauna of the Pukekura Reserve.
"We have been dealing with all the cancellations and trying to figure out how we can plan ahead . . . It has been really stressful," she said.
