The blue whale is easily the biggest animal on Earth. A blue whale’s head is so wide that an entire professional football team — 50 people — could stand on its tongue.

Its heart is as big as a small car, and its arteries are wide enough that you could climb through them. At birth, a blue whale calf is about 25 feet (7.6 m) long and weighs more than an elephant. And they do grow up very fast: During the first 7 months of its life, a blue whale drinks approximately 100 gallons (379 liters) of its mother’s milk per day, putting on as much as 200 pounds (91 kg) every 24 hours.

An adult blue whale can eat more than 4 tons (3.6 metric tons) of krill, a tiny shrimp-like creature, every day.