Radscorpion (Fallout 3)

Gameplay attributes
Radscorpions are not only powerful, but also have a nasty venomous sting that can kill the player if not treated quickly. Since they are indigenous to desert environments, they do not mind the brightly lit environments and will attack the player in broad daylight.

Radscorpions can be seen burrowing into the ground from time to time, much like their pre-War cousins. These burrows are likely where they sleep and take refuge from the harsh external environment, like heat and sandstorms.

Radscorpions will usually attack head-on and then attempt to flank the player. 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, such that even a critical hit from a high-powered weapon will only do minor damage.

Radscorpions can often send low level players running for the hills, since they can be difficult to get rid of without getting seriously injured or killed.

All radscorpions are affected by the Entomologist perk.

Radscorpion
The most common variety of radscorpion. These venomous predators seem to possess different speeds, some taking their time and others bolting at top speed. Their size ranges from that of a large dog to small livestock.

Giant radscorpion
A much larger radscorpion with an equally more potent venom. These terrifying creatures can reach incredible sizes, ranging from livestock to a Corvega. The giant radscorpion is commonly encountered usually in the west and far south of the Capital Wasteland. It's not uncommon to see one turn from the player 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 radscorpion (Broken Steel)
Albino radscorpions are about the same size as a giant radscorpion, but instead of having a dark bluish grey appearance, they are pale white with pink joints and eyes. They deal out very high damage while taking very little themselves, while 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.

Like regular radscorpions, they have no weak point, but their legs can be crippled to undermine their mobility; the dart gun is very useful in this regard, as it automatically cripples a target's legs with a hit anywhere on the body. Albino radscorpions are affected by the Entomologist perk. You can find an albino radscorpion anywhere giant radscorpions spawn. High level players may actually encounter more albino radscorpions than regular radscorpions. Albino radscorpions are one of the toughest creatures in the wasteland and should be fought at a distance.

Appearances
Radscorpions appear in Fallout 3 and its add-ons Broken Steel and Mothership Zeta.

Bugs

 * A glitch that seems to be especially frequent with giant radscorpion corpses is that they can become contorted and stretched out, sometimes spinning as well.
 * The radscorpions are prone to slipping sideways into outdoor terrain, often rendering them very slow or even immobile. This seems to be aggravated by size; the larger the radscorpion the more likely it will tilt into the ground. Giant and albino varieties may slip entirely under the terrain, but instead of plummeting to their death, will scurry towards targets from beneath the ground. Radscorpions that have slipped through in this way seem to be unable to return to the surface, but will show up as threats on the radar. Many sunk in this fashion are unable to attack although larger types seem more able to.
 * If you use the dart gun 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.
 * Much the like one of the bugs above (stating the radscorpions tilting) some of the radscorpions will be completely stuck inside the ground and cannot be seen unless using V.A.T.S..