Auto-regeneration unit
An auto-regeneration unit was a Borg device made of a polytrinic alloy. It was spherical in shape and could crawl around on its own autonomously even after its ship was destroyed.

An object suspected to be a functional auto-regeneration unit was among the technology salvaged from the debris of a Borg probe destroyed by the  in 2375. Captain Kathryn Janeway initially mistook it for a transwarp coil, until Ensign Harry Kim warned her not to touch it. ()

de: Automatische Regenerationseinheit
Borg technology