This is a new pokemon introduced in sword and shield , it is the biggest pokemon that is now bigger than the massive Wailord which is 47 feet and Eternatus at about 70 feet, (not exactly 70 feet).Also in it's pokedex entry ,it has a core it it's body to get energy from the galar region in order to stay active.

The biggest, most powerful, and scariest pokemon in the world is eternatus.

Used by true legends. In the name of gods is where eternatus is appropriate.