Imagine your friend's wincing face when the mailman hands him/her this package or the mail guy at work walks this to their desk. It’ll be glorious! MUAHAHAHA
Totally anonymous or leave a note. Choose “Add Gift Options” during checkout and leave your note.
Upgrade to make them sign for it. Choose Expedited Shipping to upgrade your prank and make them sign for the package. They’ll have to sit there signing a slip while the mailman silently judges them.