Trespasser

Trespasser is a Kaiju that passed through the inter dimensional portal at the bottom of the ocean and attacked the ctiy of San Francisco killing thousands as it destroyed buildings and land marks alike, before being killed by a nuclear bomb deployed by the Military, costing many more lives form the blast that finally killed the creature.

The Trespasser is the first Kaiju created and sent through the portal to wipe out mankind by it's masters the "Precursors", this event was known as K-day as it marked the first of many Kaiju attacks on mankind. Trespasser is a minor villain in the 2013 film Pacific Rim.