The image is of a sperm whale Physeter macrocephalus.
"Sperm whales have the largest brain of any animal (on average 17 pounds (7.8 kg) in mature males)".[1]
These sentient whales have the largest brains that have ever existed on Earth.
"Absolute size is the most general of all brain properties [...], and ranges in mammals from brains of small bats and insectivores (weighing less than 0.1 g) to those of large cetaceans (up to 9000 g)."[2]
