Thanks for the Easter greetings. Same greetings to you!
RegularUser object is always created by default. It is a member of the SystemUser group. All objects that are members of this group have mandatory user name, password and access level. Thus, you can create your own "users" if you add them to the SystemUser group. Or you can use the predefined RegularUser object.
Please read more about RegularUser BO and SystemUser group in the User Guide.