No. You won’t ever get sued by Santa Claus for using his image on Twitter. But Twitter did just pass a new rule: you can use images of others in your Tweets only with their permission. Please click here to learn more.
Even if you don’t use Twitter, the foregoing is still relevant to your use of other people’s images in, say, advertising or other public communications. This rule is related to the right of publicity: every person has a right not to have his or her image used without their permission. There are some contours to this rule from state to state, such as for public figures and issues of public concern. But you should be aware that posting another person’s image without their permission is not without risks.
In the meantime, I wish you a joyous Christmas and fresh new start to 2022.