A Florida family is reporting that their son's Elmo Knows Your Name toy has turned nasty since its batteries were changed.

Instead of singing cute songs and telling jokes to its 2-year-old owner, James, Elmo made death threats when the toy's belly was squeezed, issuing the chilling "kill James" apparently in a "sing-song voice".

"It's not something that really you would think would ever come out of a toy", said the Melissa Bowman, James' mother. "But once I heard, I was just kind of distraught."

Fisher-Price has issued the family with a voucher for a new Elmo and is "investigating" the incident. We're unsure at this stage if that includes a quick check for voodoo soul transfers from rampaging serial killers...