Miss Piggy and Captain Kirk are both from Iowa by birth, so they are Iowans. Miss Piggy is a Muppet character who, according to Frank Oz in a 1979 interview, grew up most likely in Keystone, Iowa. Captain Kirk (from Star Trek) is also famously from Iowa. The crossword clue "Like Miss Piggy and Captain Kirk, by birth" has the answer "IOWAN," meaning someone from Iowa.
Additionally, Miss Piggy's full given name is Pigathia Lee, though she is almost always known simply as Miss Piggy.