The Gantrithor was a Protoss Carrier, commanded by Executor Tassadar. It is the most famous of several heavily armed "super Carriers".[1]
The Gantrithor was powerful enough that it single-handedly defeated an entire terran battlecruiser squadron under the command of General Edmund Duke. Tassadar later sacrificed himself and his ship to destroy the zerg Overmind when it manifested on Aiur.[1]
The Gantrithor above Aiur.
Tassadar commanded the Carrier on an expedition to Char and returned in it to Aiur, where he and the rest of the Protoss fought the Zerg threat. The Gantrithor was destroyed when Tassadar called together the energies of the Dark Templar and rammed directly into the Overmind, destroying them all but saving Aiur from the Zerg threat.