As it's name implies, it is a very large and powerful alien that uses its flamethrowers to incinerate anything that stands in its way. It is completely bulletproof, and so explosive or energy damage is usually the only means of destroying it. Using the Gluon Gun or the Rocket Launcher is effective against the Gargantua. When the Gargantua is killed, it will self-destruct and destroy things in its vicinity.
|“|| Mister, if you can get the power on, that train'll take us straight to the surface. I would try it myself, but it's a long way down to the generator room.|
And there are..."things" in the way.
|- An injured Security Guard|
In the Half-Life campaign, it is encountered in the chapter Power Up, where players do not have access to the necessary weaponry to destroy the Gargantua. Instead, it must be lead into the generator room to be electrocuted, once the power is restored.
It appears once again in the chapter Surface Tension, in which the player must use the tactical map to call an airstrike to bomb the Gargantua and destroy it. However it is not necessary for progression.
|Black Mesa||Scientist · Security Guard|
|HECU||Grunt · Engineer · Medic · Sergeant|
|Black Ops||Female Assassin · Male Assassin · Bodyguard|
|Aliens|| Alien Controller · Alien Grunt · Alien Slave ·
Baby Gargantua · Baby Headcrab · Baby Voltigore · Barnacle · Bullsquid · Chumtoad · Gargantua · Gene Worm · Gonarch · Gonome · Headcrab · Houndeye · Ichthyosaur · Kingpin · Leech · Nihilanth · Panthereye · Pit Drone · Pit Worm · Shock Roach · Shock Trooper · Snark · Stukabat · Tentacle · Voltigore · Xen Commander · Zombie
|Machines||Large Mounted Turret · Small Mounted Turret · Sentry Turret · Robot Grunt|