I recently watched Norman Mailer's 1968 film WILD 90, and was amused to hear the character played by Mickey Knox telling a story about a bird and a pile of shit - the exact same story that Terence Hill would tell some five years later in MY NAME IS NOBODY, produced and co-directed by Sergio Leone! Knox wasn't directly involved with that film, but did work in various capacities on Leone's THE GOOD, THE BAD AND THE UGLY and ONCE UPON A TIME IN THE WEST, so there's clearly a connection. Mailer was later asked to write a draft of the ONCE UPON A TIME IN AMERICA screenplay, and it was Knox who introduced him to Leone.