Pesto was hatched 30 January 2024 at the Sea Life Melbourne Aquarium, and weighed 200 grams (7.1 oz) at birth. His biological father is Blake, another king penguin living at the aquarium,although keepers opted to have two younger penguins, Tango and Hudson, raise Pesto as foster parents. Pesto was the first king penguin chick to be hatched at the aquarium since 2022.Pesto was first put on display at the aquarium in April 2024.

At the time of his gender reveal in September 2024, which was broadcast on social media, he weighed 21 kilograms (46 lb), making him the largest king penguin chick to ever live at the aquarium. By that month, he was eating about 25 fish per day and 24 kilograms (53 lb) of fish per week, a healthy quantity for adolescent penguins. As of 23 September 2024, Pesto was reported to be 90 centimetres (35 in) tall and weigh 22.5 kilograms (50 lb); adult king penguins typically weigh between 9.5 kilograms (21 lb) and 18 kilograms (40 lb). Despite being a chick, he weighs more than his parents Hudson and Tango combined, although he is expected to lose weight after fledging. According to his keepers, he is expected to weigh around 15 kilograms (33 lb) as an adult. Sea Life Melbourne Aquarium partly attributed his large size to genetics, as his biological father Blake is the largest penguin at the aquarium, and partly to care by his foster parents.