"Surprise" is the first rule of comedy, and Saturday Night Live has had its fair share of surprises over the years. If someone standing on the stage isn't a host, musical guest, featured player, or regular cast member, then he or she falls under the category of "special appearance," and these appearances have created some of SNL's most memorable moments.

Whether it was Andy Kaufman doing his "Foreign Man" character, Art Garfunkel surprising audiences to sing with former partner Paul Simon,

or an awkward backstage encounter between Mike Myers and Kanye West, these one-offs are in a class all to themselves.

Here's a grab bag of especially notable special appearances that not only took audiences by surprise but also made them laugh.