The Battlecruiser Hyperion is Marshall Jim Raynor's flagship in Starcraft. It is significantly tougher than a normal battlecruiser (of the order of 900 hp), but has weapons of about the same power (30 damage to air and ground). It is more durable, but less powerful the the Norad III, the other battlecruiser 'hero' in the game (whose stats are, IIRC, 750 hp, 50 damage).

IMHO the battlecruiser is the best unit in the game. It is well worth leading your strike force with the Hyperion if you have it, not least because you then get a normal person's voice and not a quasi-russian Admiral's.