An impressively hefty penguin chick is winning the hearts of fans around the world for his sheer size and fluffiness.

Pesto the king penguin chick at Sea Life Melbourne Aquarium is less than 10 months old but already towers over both of his parents, Hudson and Tango.

He weighed in at a whopping 21 kilograms earlier in September and – with a solid diet of dozens of fish a day – is double the weight of his parents and the biggest chick to hatch at the aquarium.

“He has brought immense joy to everyone here at Sea Life Melbourne and to penguin fans around the world. We look forward to sharing his future adventure – which will include fledging and then swimming lessons,” general manager Claire Burrell said earlier this month as the aquarium conducted a general reveal for its star chick.

Pesto’s fame has already gone far and wide, but he got another boost on Monday with singer Katy Perry sharing a Sea Life video featuring him with some aquarium staff dancing to her hit Lifetimes.

Senior keeper Michaela Smale described the famous chick as “a chunky baby”.

“He gets eight fish four times a day, plus his parents also get additional feeds every day and they regurgitate fish to him as well. I don’t really know how much he is getting in total but at least 32,” she told ABC TV on Monday.

“It is normal for chicks to be a little bigger than their parents, but Pesto is on the upper percentile of that.”

Smale said it wasn’t uncommon for chicks to be bigger than adult penguins. They use the baby fat to stay warm and provide energy for fledging, when their downy baby feathers are replaced with adult feathers.

“During that time, it takes energy. He will deflate like a balloon and will come out sleek when the adult feathers come through,” she said.

Pesto is also yet to begin swimming, with aquarium staff hoping his parents will soon begin teaching him.

“They are great parents. They do a great job of protecting their young from other birds. Pesto is big enough to hold his own, but dad Hudson sticks around to make sure,” Smale said.

In the meantime, he’s a big hit on Sea Life’s social media and with visitors.

“We have guests coming in at the front desk making sure Pesto is here. He is not going anywhere. He is always here and he has a massive following interstate, internationally. Everybody loves him,” Smale said.