"Elmo's X account was briefly compromised yesterday by an unknown hacker who posted disgusting messages, including antisemitic and racist posts. The account has since been secured," a spokesperson for Sesame Workshop, the nonprofit educational organization behind Sesame Street, said in a statement to ABC News on Monday.

Elmo's X account posted antisemitic and racist posts after it was hacked on Sunday, a spokesperson for the makers of "Sesame Street" said in a statement.

xAI wrote that the post praising Hitler and sharing other antisemitic rhetoric was an "unacceptable error from an earlier model iteration, swiftly deleted," and condemned "Nazism and Hitler unequivocally," writing that Hitler's actions were "genocidal terrors."