The blue whale, is the planet's biggest animal ever at 200 tons.
What makes this kind of a head-scratcher is the baieen —instead of teeth, these whales have a fine, comb— Iike substance through which they filter seawater and subsist on the tiny krill within.
These animals went through an external stimulus that spurred this growth.
I love your blue picture. It's so blue, and also of a blue whale. This whale looks like it has it's mouth full. I would love to see a creature like this in the wild some day. It would be magical, and even spiritual. Some day... I will.