The Kimeran Juggernaut was an extremely powerful battlecruiser.
It took part in the final defense of the Kimeran Pirates against mercenaries hired by Infested Stukov. It was destroyed along with the rest of the Kimerans.
Notes
Its relation to the Kimera, another Kimeran Pirates battlecruiser with standard stats but lore-based stealth and teleportation abilities, is unknown.
References
2001-01-31. StarCraft: Brood War. Vivendi Games. Mission: Mercenaries II (in English). Map Archives: Mercenaries II.