2008 — March 17, Chuck Lorre, Lee Aronsohn & Dave Goetsch, "The Cooper-Hofstadter Polarization", episode 9-1 of The Big Bang Theory, 00:07:55-00:07:58:
Leonard Hofstadter : Not to mention, Sheldon is bat-crap crazy.
2010 — Kate Brian, Vanished, Book 13, Simon & Schuster (2008), →ISBN, page 15:
[…] … and of all the people we'd trusted who'd turned out to be completely bat-crap crazy.
2010 — Joshilyn Jackson, Backseat Saints, Grand Central Publishing (2011), →ISBN, unnumbered page:
Her mama bounced in and out of the nuthouse, and a bat-crap crazy mother seemed a flat step down, even from a willfully missing mother like my own.