A cobalt bomb was an explosive device with greater destructive power than standard nuclear weapon.
A number of advanced races had access to cobalt bombs or the technology to create them. These included:
- Qataka (PROSE: Timewyrm: Genesys)
- Greld (PROSE: The Empire of Glass)
- Waro (PROSE: The Devil Goblins from Neptune)
- Cybermen (PROSE: Iceberg)
- Klytode (COMIC: The Snag Finders)