The Internet’s favorite penguin begins to grow up and lose the stuffed animals that made him famous.

Pesto the penguin, a king penguin at Sea Life Aquarium in Melbourne, Australia, was one of two animals at the zoo that caught people’s attention last month. The other was Moo Deng, a newborn pygmy hippopotamus at a zoo in Thailand, as previously reported Desert News.

The two adorable internet sensations sparked debates over who was the public’s favorite, with both racking up millions of views on social media.

Pesto became a hit due to its large size, earning it the nickname “linebacker.”

In one particularly popular video, Pesto waddles next to an adult penguin, looking like a giant in comparison.

According to CNNAt 9 months old, Pesto already weighed 50 pounds and was 3 feet tall, making him heavier and taller than his parents.

The aquarium explained on its website that Pesto’s size is due in part to his biological father, Blake, who is the oldest and largest penguin at the center. Pesto has his “good genes,” the aquarium said.

Additionally, Pesto healthily eats 25 fish per day.

Recently, Pesto has attracted attention again as it begins to grow and fly away, which is when baby king penguins lose their brown adolescent feathers and develop the more recognizable white, black and orange adult plumage.

For some fans, the transition is a bittersweet moment, as they came to love Pesto’s brown, fluffy feathers, which added to his unique charm.

According to BritishKing penguins are the second largest penguin species, after emperor penguins. They typically weigh between 31 and 37 pounds and stand between 33 and 37 inches tall. In comparison, emperor penguins weigh between 55 and 100 pounds and are about 50 inches tall.

This has led some fans to wonder if Pesto might have a bit of emperor penguin in his genes.

Britannica also notes that king penguins typically begin moulting their brown plumage between 10 and 12 months of age, and complete the fledgling stage around a year old. In the wild they live for around 26 years, while in captivity they can live up to 41 years.