The first formula for the Mutant Dinos' mutation was written as early as 2001 by Evil Ogel. However, he decided against using it, as he feared that the Mutant Dinos would be too powerful and dangerous, and could thus turn against him and his drone armies. However, he left this formula in one of his bases, and this base was infiltrated by two Alpha Team agents: Dr. Rex and the original Frozeen. Frozeen was unaware of the formula's existence, since Dr. Rex had kept it a secret and hid it away after stealing it.
In 2010, Dr. Rex was under the influence of Baron Typhonus. He believed that Minifigkind was doomed to destruction, and that mutant dinosaurs were destined to rule the LEGO Planet. He uncovered the Mutant Dino formula and used it to mutate four specimens, which would be considered the 'prototype' Mutant Dinos, one of which was Rex. Dr. Rex decided that these Mutant Dinos were not enough, and so altered the formula to include the energies of the Maelstrom, granting the mutants extraordinary powers.
In April 2010, after a large number of these powered Mutant Dinos were mutated by XERRD, Dr. Rex began to allow them to spread all over the LEGO Planet by means of teleportation and sneaking aboard cargo ships. The Mutant Dinos devastated the planet, leaving cities in ruin and killing many Minifigs in their rampage. This event, known as the "Dino Attack", led to the creation of the Dino Attack Team to combat these creatures.
The Dino Attack continued for the rest of the year, and the Mutant Dinos continuously clashed with the Dino Attack Team in places such as LEGO City, LEGO Island, and Adventurers' Island. Some idealist Dino Attack agents preferred to capture and tame Mutant Dinos, giving them the willpower to overcome Dr. Rex's control. However, as Dr. Rex's grasp on the Maelstrom grew, the Mutant Dinos were forced to bend to his will and form his personal army. Even worse, as the Maelstrom's power also grew, the Darkitect drove the Mutant Dinos' urges to destroy, making them even more dangerous.
On December 21, 2010, Dr. Rex gathered as many Mutant Dinos as he could and attacked LEGO City, with the intent of destroying Dino Attack Headquarters and defeating the Dino Attack Team. Despite the overwhelmingly large Mutant Dino army, Dino Attack Team and its allies were able to hold off against the dinosaurs long enough for the Einstein Device to be finished. Once the Einstein Device was fired, the resulting Imagination fallout wiped out most of the Mutant Dino army.
With Dr. Rex dead and the Darkitect forever banished from the LEGO Planet, the surviving Mutant Dinos were left without anyone controlling them, leaving them wild and aimless. Over the following months, the Mutant Dinos were hunted down by Dino Attack Team and either killed or cured, the latter in part by a Mutant Dino cure developed by XERRD under Dr. Cyborg's leadership.
The venom used to mutate the Dinos has been analyzed by the Dino Attack Team, who have managed to find semi-cures for it. However, the wing of Dino Attack Headquarters which contained these cures has been wrecked in a Mutant T-Rex attack, and many of the cures were lost.
In the Dino Cop-inspired Mutant Dino Serum, the DNA of any Mutant Dino is capable of overriding any other DNA sequence, resulting in a transformation capable of turning even Minifigs into Mutant Dinos. For example, if a Minifig is injected with Mutant Lizard DNA, the Mutant Lizard DNA will override the Minifig's DNA, and the Minifig would transform into a Mutant Lizard. Dino Attack Agents such as Snake of Spades and Amanda Claw have been mutated in this manner, and Dino Attack has been able to find some ways to "cure" these agents as best as possible.
The Maelstrom, a dark destructive force of the LEGO Universe, is a primary part of the formula to mutate the Mutant Dinos and grant them their abilities. Because of the Maelstrom, Mutant Dinos tend to be destructive and hostile by nature, and during the Dino Attack they have destroyed much of the LEGO Planet. It has been shown that, usually with the help of other beings, Mutant Dinos can build their willpower and overcome the urges to destroy. When a Mutant Dino has built enough willpower to break free of the Maelstrom's control and Dr. Rex's enslavement, they are considered "immune" to the Maelstrom's influence.
Dino Attack agent Amanda, who had spent approximately a month as a Mutant T-Rex, noted that being Mutant Dinos induced brain spasms and shortened her temper. This suggests that because the mutation is unnatural and connected to the Maelstrom, it has unhealthy side-effects. Mutant Dinos also seem to dislike the mutation and want to keep others from undergoing it, as evidenced when an unidentified Mutant Raptor told Rex and Chompy to turn back when they were heading for the Dino Island Laboratory.
Mutant Dinos also seem to share a universal language, and all four breeds can communicate with each other with ease. At first glance, Mutant Dinos may seem like unintelligent beasts, but those who can translate their universal language have discovered that Mutant Dinos are actually quite intelligent, such as Trouble or Tex. This has raised moral debates amongst the Dino Attack Team.
There are four standard breeds of the Mutant Dinos. Each breed has been mutated to have a special power. Among the Lizard breed, however, there are many sub-breeds that individually have separate powers.
Mutant Lizards Edit
All Mutant Lizards have increased speed, even compared to their un-mutated versions. Mutant Lizards are the breed with the most variety. The powers of Mutant Lizards vary, from chameleon abilities to acid, or from heightened stealth to fire-breathing. They are the most common breed and are encountered the most by Dino Attack, but primarily in large groups where they are the most dangerous. They are skilled at infiltrating Dino Attack bases and at adapting to tactics used against them.
Mutant Raptors Edit
Mutant Raptors are considered the perfect hunters. With enhanced sight and hearing, they can track down any prey and are strong enough to tear even a Fire Hammer to pieces. In addition, they possess force fields that shield them from most attacks, although they are vulnerable to the Dino Attack Team's Cosmotronic Rays.
Mutant Pterosaurs Edit
Mutant Pterosaurs are the masters of the skies. They possess incredible skill, speed, and agility, making them difficult to shoot when they are in flight. They also fire lightning bolts from the tips of their wings, allowing the Mutant Pterosaurs to shoot down aircrafts or rain electricity on unfortunate prey down below.
Mutant T-Rexes Edit
Kings of the Mutant Dinosaurs, the Mutant T-Rexes are the ultimate danger to the LEGO Planet. They can demolish buildings with one sweep of their tails or bite through solid steel. Their laser vision protects them from aerial attack, and their mouths are internal furnaces that can disintegrate almost anything they close their jaws upon.
Other Species Edit
Several other species of mutant dino have also appeared, some of which aren't even dinosaurs, simply injected with mutant dino DNA, notable examples include the Octosaur, and Mutant Viking monsters. Though not a true hybrid, the Mutant Tyrannosaur Tex's DNA was affected by Draconic magic, giving her dragon-like abilities and traits, such as fire-breathing, telepathy and speech. The Quasifigus Hybrids, such as the Minifig/Mutant Lizard Hybrid, are biologically-engineered hybrids of Minifigs and Mutant Dinos.
- Prior to Dr. Rex's introduction, many different explanations of the origin of the Mutant Dinos have been used throughout Dino Attack RPG. Canonically in the RPG, XERRD is responsible for most Mutant Dinos.
- On the Official LEGO Dino Attack Website, it hints that the Mutant Dinos are actually robotic. According to LEGO designer Mark Stafford, this was the original intention for the dinosaurs to be robotic, not mutants. However, this explanation has been disregarded in the Dino Attack RPG, due to LEGO's marketing team describing these dinosaurs as mutants in other media, leading the RPG players to misinterpret the hints to the Mutant Dinos being robots as merely being metaphorical. The Robotic Mutant Dinos in the RPG, as well as Adventure's Terminator-referencing quote in First Assignment, exist as a nod to this original concept.
- Due to the Maelstrom's role in their mutation, Mutant Dinos are unofficially considered Stromlings. They are more intelligent and independent of the Maelstrom than most Stromlings, but as the Maelstrom's strength grew and as Dr. Rex continued to harness its power, the will of many Mutant Dinos was bent to that of the Maelstrom. The four prototype Mutant Dinos, whose mutations did not involve the Maelstrom, are not Stromlings.
- The four prototype Mutant Dinos all ended up working with Dino Attack Team. Rex joined the Dino Attack Team as a result of a failed plan by Dr. Rex to destroy the team, and the other three eventually joined Pterisa in her journey to aid the Dino Attack Team.