Generic catch-all error template Is there a catch all error page template?

I'd like to use http://http.cat for my statuses.

(originally asked by Bryan Redeagle in Craft Slack)
Yes — an error.twig template in your error templates directory serves as a catch-all template when a more specific template (e.g. 404.twig) can't be found, or when the system throws a general error that doesn't have a status code attached.

(You can customize the path prefix for error templates by changing the errorTemplatePrefix setting in the Craft General Config.)