Radscorpions are mutated from the North American Emperor scorpion, which were common in many pet stores at the time of the Great War. Contrary to many expectations, their venom grew much more potent and deadly when they mutated rather than becoming diluted. Though considered nocturnal and sensitive to light, radscorpions can be found active during the daytime in the areas they inhabit. Apart from their size, they appear visually identical to regular scorpions, with thick, mottled, dark, blueish gray carapaces. Their poison gland is used in crafting the dart gun.
Radscorpions are not only armed with two powerful claws but also have a nasty venomous sting that can kill victims if not treated quickly. Since they are indigenous to desert environments, they do not mind brightly-lit environments and will attack anyone in broad daylight as well as at night. Radscorpions can be seen burrowing into the ground from time to time, much like their pre-War counterparts. These burrows are likely where they sleep and take refuge from the harsh conditions of the external environment, such as intense heat and sandstorms.
Radscorpions will usually attack head-on and then attempt to flank their prey. Unlike other creatures, radscorpions lack a "weak point" that can be targeted for extra damage (such as a "head" for a headshot), which makes V.A.T.S. combat and firearms somewhat less effective against them. Radscorpions also take significantly reduced damage from any shots that hit their legs, meaning that even a Critical Hit from a high-powered weapon will only do minor damage. While close-by or indoor, radscorpions will make a distinct "walking sound" that gives their presence away, though it may happen that a radscorpion stays idle until it notices the target. All radscorpions are affected by the Entomologist perk.
The most common variety of radscorpion. These venomous predators seem to possess varying speeds, some taking their time and others bolting at top speed. Their size ranges from that of a large dog to small livestock.
A much larger radscorpion with a much more potent venom. These terrifying creatures can reach incredible sizes, ranging from livestock to a Corvega. The giant radscorpion is commonly encountered in the west and far south of the Capital Wasteland. It is not uncommon to see one turn from the target and back off, only to be joined by another and charge in again. In fact, they seem to operate in pairs most often, only preferring to attack alone when their partner is dead.
Albino radscorpions are about the same size as a giant radscorpion, but instead of having a dark bluish-gray appearance, they are pale white with pink joints and eyes. They are capable of dealing and withstanding a very large amount of damage, are significantly more maneuverable than regular radscorpions, and their stingers contain an extremely potent venom. They are exceptionally tough and have significantly more hit points than almost any other creature or non-player character in the game, surpassed only by a super mutant behemoth and General Jingwei. A unique trait about these radscorpions is the fact that they slowly regenerate health when exposed to direct sunlight, similar to the effect of the Solar Powered perk.
Like regular radscorpions, they have no weak point, but their legs can be crippled to undermine their mobility. An albino radscorpion can be found anywhere near a giant radscorpion spawn, and they can be encountered in pairs or appear after fast travel. Well-prepared and high-level travelers may actually encounter more albino radscorpions than regular radscorpions. As evident by their statistics, albino radscorpions are one of the toughest creatures to be fought in the Wasteland.
Targeting their stinger does not affect the ability to collect poison glands, even if the killing shot depicts the stinger being blown off.
It is possible to find a non-hostile giant radscorpion wandering the Wasteland, as part of a random encounter. It will attack raiders, creatures, and any other hostile characters it comes across. Companions, however, are likely to attack it. It may run away if wounded and if the Lone Wanderer goes near it, it will start fighting them.
Usually, one or more giant radscorpions (at high levels, they will most likely encounter albino type) will spawn just outside Regulator HQ, and be attracted to the mooing of the brahmin outside. They usually target the brahmin first, unless they spot the Lone Wanderer. This is quite common when fast traveling.
An Enclave research terminal states that the giant radscorpions are "just exaggerations" made by the operatives.
It is odd that albino radscorpions will slowly heal in sunlight since albinism is usually associated with extreme sensitivity to sunlight.
Radscorpions are physically long creatures and therefore have a wider and slower turn radius. However, albino radscorpions do have a higher movement speed in general.
Radscorpions tend to emit a sharp hissing sound whenever they use both their pincers and their tail as they attack.
Radscorpions walk backward if either charged by the Lone Wanderer or take damage from a significant melee attack, such as from a deathclaw, which makes it easier for Unarmed and Melee oriented characters.
An Enclave field research terminal at a small outpost west of the Temple of the Union summarizes Enclave observation and testing of radscorpions. The researcher believes the radscorpion is a mutated pandinus imperator (emperor scorpion), though more study is required to identify it precisely. The researcher notes that the radscorpion's stinger has enlarged, along with its venom glands. The neurotoxins that the radscorpions administer now act on potassium and calcium channels of the victim as well. The subject tested by the Enclave was noted to be a hostile, albeit minor, threat that would be problematic in larger numbers. Finally, the researcher states that rumors of larger subjects exist, but casts the rumors off as exaggerations. As the size of the camptive radscorpion is not known, it is possible that these "larger subjects" could refer to giant or albino radscorpions found in the Capital Wasteland, even larger variants such as the radscorpion queen found in the Mojave Wasteland, or hitherto unseen variants.
If the dart gun is used against two giant radscorpions (shooting a dart at one first and a second dart at the other one), the weakest one will disappear from sight while the other is still engaging. [verified]
A giant radscorpion can be found at the Super-Duper Mart early on in the game. [verified]