Create a clone of an existing virtual machine (VM). More information: https://www.virtualbox.org/manual/ch08.html#vboxmanage-clonevm.
VBoxManage clonevm {{vm_name}}
VBoxManage clonevm {{vm_name}} --name {{new_vm_name}}
VBoxManage clonevm {{vm_name}} --basefolder {{path/to/directory}}
VBoxManage clonevm {{vm_name}} --register