Pat's Pond was briefly hijacked by a URL-selling company. Fortunately, these attacks have been reported to BlogSpot. Another blogger simply looked for the additional garbage among the HTML in the template.
I searched for those idiots by their url, and sure enough, there it was nestled comfortably in my code.
Ripped it out by the roots.
Jerks. Everyone be warned. The correction is simple and can be done right in Blogger.