Biolizard

The Biolizard (バイオリザード) is a character that appears in Sonic Adventure 2 and Sonic Adventure 2: Battle. He was the first prototype of the ultimate life form created by Gerald Robotnik during Project Shadow, but was far too dangerous and flawed. After the final version of the ultimate life form, Shadow the Hedgehog, was created, the Biolizard was encapsulated by GUN, but was later used by Gerald Robotnik as a part of his plan to destroy the earth to avenge his dead granddaughter, Maria Robotnik.
 * For the character in Sonic X, see Bio Lizard. For the character in the Archie Comics, see Biolizard (Archie). For the boss battle in Sonic Adventure 2, see Biolizard (Sonic Adventure 2).

Appearance
The Biolizard was a colossal and grotesque lizard-like beast, easily over two hundred feet long from the tip of its nose to end tip of its tail, about one hundred feet wide, and about sixty feet tall at the tallest point on its back. It had flame skin with a dark grey underbelly, and possessed a long neck, a flat and almost round torso with gill-like flaps on the sides, and a thick tail. It also had two stubby and thick forelegs, each with three thick toes on a foot inextinguishable from the leg, and four short flippers on the rear. Additionally, it had a large and pale toothless mouth with black lips and four yellow spikes on the lower jaw. On its neck, back, hinder quarters and tail, the Biolizard had yellow patches of skin.

The Biolizard had several robotic parts implants. Its eyes were like gun-turrets and it had a large disk-shaped machinery with a red orb in the middle on its back which was its life support system. It also had several cables on its back and a set of green cables on its jaw joints connecting with its life support system, along with a stump of green cable on its forehead. It also seemed to have vents near the foot of its neck.

Early life
The creation of the Biolizard was conceived when "Project Shadow" was launched by the President of the United Federation. This government project, led by Professor Gerald Robotnik, was intended to create an "ultimate life form" for humanity to research immortality with and create an "immortality formula" for war. However, Gerald's own motives for creating this creature was to use the immortality research from the project to develop a cure for a fatal disease afflicting his granddaughter, Maria Robotnik.

The Biolizard was created by Gerald onboard the Space Colony ARK as the first prototype for the ultimate life form and was made in the image of a lizard. At 12:30 A.M. on the 27th of January, the Biolizard was successfully brought to life, with his eternal engine and Chaos Control-inducing organ working normally. However, because the measurements of the experiment were higher than expected, the Biolizard was moved to the Central Dome for further tests.

As he grew, the Biolizard showed many of the researchers' desired traits, including regeneration, restoration, and self-reproduction, but he required a life support system fueled by Chaos Drives to sustain himself. Over time, the Biolizard proved too flawed. Besides having an unexpected and exponentially fast growth rate (growing to be 2,7m long and weighting 350 kg in just a couple of days) that strained his vital organs' control parts, he possessed a mind of a primitive animal, reacted violently to the Chaos Emerald's power, and was too weak to walk at that time. As such, it was required to keep him under observation. Over time, the Biolizard became unruly and hard to control, causing many problems onboard the ARK. In the end, the Biolizard was abandoned when Gerald produced a more advanced being with Black Doom's DNA: Shadow the Hedgehog.

Eventually, the private information about the Biolizard's violence somehow leaked to GUN, supposedly by those on the ARK fearing him, which made the government deem Gerald's work a danger to humanity. When GUN invaded the ARK to eliminate everything related to Project Shadow, the Biolizard was found and encapsulated in the deepest part of the ARK. He did not go down without a fight though, and he destroyed almost the entire group of GUN soldiers before being subdued. When Gerald later tried to destroy Earth to avenge Maria's death by having the ARK collide with the planet once the seven Chaos Emeralds were inserted in the Eclipse Cannon, the Biolizard was retrieved by Gerald and programmed to ensure the ARK would stay on its collision course in case someone would interfere.

Sonic Adventure 2
In Sonic Adventure 2, the Biolizard had remained in suspended animation for over fifty years until Dr. Eggman initiated Gerald's program that sent the ARK falling towards Earth when trying to use the fully-charged Eclipse Cannon. When Sonic and Knuckles came to Cannon's Core to stop the ARK by deactivating the Chaos Emeralds, the Biolizard awakened and appeared in front of them, blocking their path to the Emeralds. However, Shadow then arrived to keep him at bay. Despite his best attempts, the Biolizard was defeated when Shadow managed to damage his life support system.

After Knuckles stopped the Chaos Emeralds, the Biolizard made a fast recovery and used Chaos Control to teleport outside of the ARK and fused with the space colony itself, becoming the Finalhazard, to keep it on its collision course. Shortly after, he fought both Super Sonic and Super Shadow, but was defeated and destroyed as the ARK entered the atmosphere.

Shadow the Hedgehog
The Biolizard made an appearance in Shadow the Hedgehog, but only in one of Shadow's flashbacks, when he remembers his apparent death after defeating it. His faint cries can also vaguely be heard in the background of The Doom, which is set at the time the Ark was raided by GUN, probably referencing the battle to contain the Biolizard that went on while Shadow was trying to save Maria.

Sonic Rivals 2
The Biolizard made an appearance in Sonic Rivals 2 as one of the collectible cards. To collect it, the player has to complete Knuckles' storyline in single player or unlock Knuckles' Armor Suit.

Sonic Generations
Modern Sonic fights the Biolizard in the Cannon's Core in the Nintendo 3DS version of Sonic Generations. The boss fight remains somewhat unchanged from his Sonic Adventure 2 appearance except done on a 2D plane. He also seems to have gotten stronger as at times, balls of light can appear in front of Sonic as he runs from the Biolizard's head or tail, which must be jumped or slid under. He also has a new tail slam attack and he chases Sonic as he tries to crush him with his tail.

Personality
Unlike Shadow, the Biolizard was more like a primitive animal, possessing a low intelligence and learning ability. It was extremely unruly, reckless and hostile, causing so many troubles that the researchers onboard the ARK feared for their lives. Additionally, it was sensitive to temperature and humidity changes, and would react violently when possessing the power of the Chaos Emeralds.

Powers and abilities
As the prototype of the ultimate life form, which was aimed to have immortality, the Biolizard has the abilities attributed to the desired end-product, though the various experiments had severely weakened it, and it required a life support system to stay alive. It possessed a regenerative healing factor which let it restore itself quickly whenever it was injured and fully regenerate any lost limbs. It could as well asexually self-reproduce itself by creating pinks eggs seemingly out of nowhere.

The surface of the Biolizard's skin was designed to absorb all outside attacks. With its life support system aiding it, the Biolizard's skin could resist attacks to such a degree that they would just bounce off it, making it virtually invulnerable. Additionally, the Biolizard was noted to possess a physically strong neck and tail. While it was also not able to walk at one point, it was a very fast crawler, being able to keep up with both Sonic and Shadow's running by crawling.

The Biolizard could project dark energy balls from its mouth and direct them in curved formations. It also had either telekinesis or a limited ability to manipulate gravity, which it could use to either lift opponents helplessly into midair or move and repulse objects, allowing it to turn its eggs into projectiles or arrange them in different formations. The Biolizard was also capable of harnessing chaos energy from the Chaos Emeralds and could perform Chaos Control (through a special organ) which let it warp both time and space.

The Biolizard's main weakness was its own flawed design. It relied heavily on the power of its life support system and should it be destroyed it would leave it vulnerable. It also appeared to have low stamina, as it would quickly exhaust itself with its attacks.

Finalhazard
By merging with the Space Colony ARK at the tip of the Eclipse Cannon, the Biolizard could transform into the Finalizard. In this form, it could harness the energies of both the ARK and the Chaos Emeralds, allowing it fight on par with both Super Sonic and Super Shadow. Additionally, it could fire energy beams, and its gravity manipulation was more refined. However, because its life support system had been demolished, the harsh conditions of space would create boils on its body which proved to be vulnerable spots.

Battle
The Biolizard appears as the preulimate boss in Sonic Adventure 2 and Sonic Adventure 2: Battle, and the second boss in the Nintendo 3DS version of Sonic Generations. During each battle, the player has to evade the the Biolizard's bites, energy balls, tail whips, and egg projectiles until it tires and then attack the life support system on its back to damage it.

Sonic X
The Biolizard also appears in the anime Sonic X, where it is named the Bio Lizard and its role parallels the one it plays in Sonic Adventure 2. Like in the games, it was created onboard by Professor Gerald, but was sealed away when the military shut down the ARK. Gerald later retrieved it and made it a part of his plan to destroy Earth to avenge Maria's death.

When Gerald's doomsday plans was put into motion by having the Space Colony ARK collide with Earth, the Bio Lizard tried to stop Sonic the Hedgehog and his allies from preventing the plan's completion, but was destroyed by Super Sonic and Super Shadow.

Archie Comics
The Biolizard also appeared in the Archie Comics' Sonic the Hedgehog and its spin-off comic book series following the Sonic Adventure 2 comic adaption. However it was not until Sonic Universe #2, which retold the story, that the Biolizard made a physical appearance.

Like in the games, the Biolizard was created by Professor Gerald, but was later used by Gerald as a part of his plan to destroy Mobius to avenge Maria's death. When Sonic and Shadow tried to foil Gerald's plans, the Biolizard attempted to make the Space Colony ARK collide with the planet, but was defeated by Super Sonic and Super Shadow.

Theme songs

 * "Supporting Me" - Everett Bradley

Trivia

 * It is often assumed that the Biolizard is female (due to the eggs), but this is unlikely because, additionally, the Omochao that appears refers to the Biolizard as a "he". The misconception is due to the fact that it appears to reproduce asexually. However asexual reproduction is largely done by species without clear gender differences and in the case of the Biolizard it is most likely that it is hermaphroditic.
 * The Biolizard was likely just an example of Gerald's work before Black Doom assisted him, and thus is of little interest to the Black Arms and was not stable because he did not have Black Doom's DNA. However, this is not confirmed.
 * It should be noted that after Black Doom transforms into Devil Doom, he has an identical cry to that of Biolizard. Several other Black Arms have similar cries. Also, the Black Annelids, Black Worms, and Death Leeches, have a skin texture very similar to the Biolizard's. This presents the possibility of the Biolizard actually being a Black Arms experiment, but it was simply unsuccessful. As it turns out, Devil Doom and Biolizard's cry is just a reused version of Perfect Chaos' cry.
 * When Biolizard summons the pink spheres and later levitates Shadow, the roar used is the same roar used for Perfect Chaos in Sonic Adventure, but with a different pitch. In the 3DS version of Sonic Generations, Biolizard 's roar is now reused from Dark Gaia Phoenix's from Sonic Unleashed.
 * The Dreamcast version of Sonic Adventure 2 had glitches in the game that led to unavoidable deaths when fighting the Biolizard (such as landing in the water as opposed to on the platform).
 * When playing the Dragon Slayer mission in Sonic and the Black Knight, Sonic sometimes mentions the Biolizard. The Earth Dragon, in fact, may be the Arthurian version of the Biolizard due to being so similar in body type, having the same neck, and even a similar roar.
 * After defeating the Biolizard in Sonic Generations (3DS), the following cutscene shows Sonic saying he fought it before. Technically, he did not fight the Biolizard in its normal form (it was fought by Shadow) but he did fight it when it transformed into the Finalhazard.