Outlandish person, or really anybody who would look like a cartoon character after a wardrobe change. It comes from the "Where's Waldo" series; there are bonus finds the reader can look for if they tear through all the main finds. Sometimes these bonus finds are characters that look absolutely ridiculous, like a pirate smoking a long white pipe, with a cutlass hanging from his belt and a bandolier of bullets strapped to his chest. Equivocally ridiculous people are called sidefinds. This terminology is used in the "Tasty Pint" blog.
CH: Dude, check out that old lady eating Taco Bell!
BJ: Now THAT is a sidefind...
CH: ...Totally sidefindish.