At first glance, it might have looked like a run-of-the-mill social media check-in: "How is everybody doing?" But the message came from Elmo — the furry red friend to kids, Muppets and anyone else.

When describing Elmo of "Sesame Street," the words that likely come to mind include "cute," "cuddly" and "lovable." Subscribe to read this story ad-free Get unlimited access to ad-free articles and ...