Why is Seattle called Kraken?

Could you elaborate on the reasoning behind Seattle being referred to as "Kraken"? I'm intrigued by this nickname and am curious if it stems from a historical event, a local legend, or perhaps a more contemporary reference. Is there a specific location, such as a statue or landmark, that lends to this moniker? Additionally, how widely recognized is "Kraken" as a term for Seattle among residents and visitors alike? I'd appreciate any insights or background information you may have on this intriguing nickname.