Thardus

Thardus is an enormous rock monster charged with Phazon energy that inhabited Tallon IV in the Phendrana Drifts of the Overworld. It was originally an experiment by the Space Pirates to use Phazon to create sentient creatures out of inanimate objects, but was found quarantined in a cavern in Metroid Prime. This experiment was titled "Project Titan".

Official website
"Thardus is a towering, sentient creature of stone charged with Phazon radiation. Thardus attacks its prey through a variety of well-developed techniques. It can hurl huge boulders at its prey, or curl itself into a gargantuan bone-crushing ball. Thardus is also able to encase its targets in ice, making it an extremely dangerous foe.

Thardus's body consists of dozens of boulders held together through the power of the Phazon's radioactive charge."

Battle
Thardus controls the rocks in its domain and the icy weather that resides over the drifts. Its primary attack is to animate three small rocks and cause them to rush at the enemy, these rocks can be destroyed for ammo and energy. It can also send ice spikes that encase the targer in ice, and lastly Thardus will curl up into a ball and attempt to crush the enemy.

To defeat the behemoth, Samus must use the Thermal Visor to locate Thardus's weak spot, then fire at it with a weapon, preferably with a single Super Missile. Once Samus hits the spot a few times, Thardus will release enormous amounts of thermal energy as its Phazon core is exposed, making the visor "white out". Alternatively, Samus can wait until the beast begins to roll around the room. At this point, laying a single Bomb in its path will instantly smash open the weak point.

Regardless of how the Phazon is exposed, she must then switch back to the Combat Visor and fire at the weak spot. Thardus will continually switch weak spots until the third weak spot is hit. Then it will unleash an ice storm, making it hard to see in the Combat Visor. Samus must continue the process, until the creature explodes once the sixth weak spot is destroyed, leaving behind the Spider Ball. Humorously, a large rock hits Samus in the head after she moves out of the way of the falling boulders.

In Other Media
Thardus also made an appearance in Metroid Prime Pinball, as a boss for the Power Bomb upgrade, and in Metroid Prime (comic), in the Chozo Ruins.

Mike Sneath design notes
''Many who have played the game might naturally assume that Thardus would have been one of the more complicated creatures to model because of his "rock reorganization" capabilities, but that isn't the case at all. According to Mike, "It's actually a lot more simple than that, as I know I only made one 'Thardus' model. How the programmer handled it afterwards is beyond my knowledge… Actually, Thardus was probably the easiest boss I did." The Thardus battle is only comprised of one model that was later animated to make all the different configurations seen through out the battle. Quite impressive, I must say, and yet another testament to the ingenuity of the MP programming team. Another artist added the animated particles, such as snow, dust, and rock fragments, later in development.''

Trivia

 * In Metroid Prime Trilogy, very noticable bloom lighting effects have been added to the Thardus battle.
 * Scans in Research Core indicate that Thermal Visor technology was used to transport Thardus to the Quarantine Cave.
 * Thardus is very weak to the Plasma Beam, but to obtain it this early Samus must first sequence break to get the Ice Beam (and in European and Japanese regions, the Power Bombs) early. Then she must sequence break in Geothermal Core to actually get to the beam.
 * A rock monster very similar to Thardus named "Gorignak" appeared in the 1999 Star Trek-parody film Galaxy Quest. In the film, the main character (Jason Nesmith / Commander/ Captain Peter Quincy Taggart, played by Tim Allen) comments that Gorignak is "...a rock! It doesn't have any vulnerable spots!"