Is impersonating someone in the Metaverse a crime?

In general, impersonating someone can affect the person’s personality rights. In particular, using someone’s image/likeness (e.g. by using an avatar that looks like another person) affects the person’s right to his/her own image and generally requires consent of the person portrayed. There are some exceptions to this rule, e.g. when using a likeness with reference to contemporary history.

Also, the impersonation can be covered by constitutional freedoms (mostly art, speech, press). When no such exception or freedom applies, the use of someone’s likeness (but not his/her voice!) is a criminal offense, which is however only prosecuted upon application by the affected person.