If you post a sad face emoji on Facebook now, don't be surprised if it morphs into a tiny monster face. The social networking site has introduced emojis like a laughing witch face, a crying Frankenstein face, an angry pumpkin face and so on in keeping with the spirit of Halloween, which falls on October 31. But many users aren't amused, reports The Daily Mail. Some have taken to Twitter to complain about the move. “A friend’s father died and all of the sad face emojis people posted on Facebook are now Frankenstein’s monsters,” went one tweet. It’s an embarrassing misstep for the social media giant. Recently, it had also censored a powerful Vietnam War picture on grounds of nudity. Clearly, FB needs to think certain things through before it acts.