In Fallout 3, a Mirelurk is one of the most fearsome enemies the Lone Wanderer can come across. There are several types, all considered quite deadly.
Mirelurks are humanoid mutant crabs. Most meat from creatures in Fallout 3 is fairly useless, but Mirelurk meat is much better than most in healing qualities, and worth something to traders.
The face of the Mirelurk is a weak spot, in stark contrast to its otherwise tough exterior. Mirelurks are best fought at a distance, as they are powerful melee fighters.
Mirelurk Hunters are a stronger and faster version of normal Mirelurks. They have a lot more HP and higher damage resistance (letting them recieve only 1/2 damage) making them vering tough to kill. Their high damage and their speed make them very dangerous as well. not only do they have higher stats, but they are slightly taller and have more detail on their carapace.
Being a Mirelurk, the same tactic to killing Mirelurks applies to Mirelurk Hunters as well: aim for the unprotected face.
Mirelurk Kings look very different from the regular Mirelurk and the Mirelurk Hunter due to the lack of a carapace. Because of them not having any protective layer around their skin, they're much easier to kill using V.A.T.S since the weak spot isn't as small. They do have a lot of health, but due to the low damage resistance, they are ususally easier to defeat than Mirelurk Hunters. Another factor that makes them easier to defeat is that they are usually in small groups, unlike regular Mirelurks and Mirelurk hunters.
Other than a regular melee attack, they can use a long ranged sonic attack, which instantly cripples the player's head and deals moderate damage if it hits. However, it is a very slow attack and can easily be dodged. If the Mirelurk King's head is crippled, then this attack cannot be used. Because of this long range attack and the regular Mirelurk's high damage resistance, when Mirelurk Kings are encountered together with other Mirelurks, they can be very dangerous.
Mirelurk Kings have been compared to the creature in Creature From
The Black Lagoon, released in 1954. This similarity is most probably an intentional easter egg due to the difference in appearance between regular Mirelurks and the Mirelurk King.
NukaLurks are a special type or Mirelurk which can only be found in the lower levels of the Nuka-Cola Plant. They glow blue, similar to how Nuka-Cola Quantum glows, which is most probably because of the Strontium used to make Nuka-Cola Quantum which then radiated the Mirelurk, turning them into NukaLurks.
There are two kinds of NukaLurks, in the same way that there are Mirelurks and Mirelurk Hunters. A few of the NukaLurks are taller and more vicious. The smaller NukaLurk is a little bit harder to kill than regular Mirelurks and the taller NukaLurks are more difficult than Mirelurk Hunters.
NukaLurks drop a special kind of meat which heals more than regular Mirelurk Meat and also boosts AP in the same way Nuka-Cola Quantum does. It is, however, more radioactive than regular Mirelurk Meat.