Skullcrawler

Skullcrawlers are giant reptilian Kaiju that appeared in Kong: Skull Island.

Name
Skullcrawlers got their name from their skull-like heads and their crawling locomotions. Their true name is known but unspoken by the natives, and the name "Skullcrawler" was coined by Marlow as he explained their history to Weaver and Conrad.

Appearance
Skullcrawlers are large reptilian creatures with only two long forelimbs and no hindlimbs, as well as long, prehensile, serpentine tails. They have long and slender, yet muscular, sturdy bodies. Several aspects of their appearance are noticeably skeletal, particularly their torsos and their heads. What appear to be the "eye sockets" of their skull-like heads are merely empty fenestrae: their real eyes are set much further back, with the fenestrae perhaps serving to distract enemies from their more vulnerable eyes and as heat-seeking sensory pits. The colors of their scales range from dark brown to dark green.

Their heads closely resemble those of Mosasaurs such as Tylosaurus, and their jaws possess two rows of serrated, razor-sharp teeth. The Skullcrawlers have four digits in total of each hand, with the thumb being the smallest digit and the rest of the digits being larger and of the same size, and a prominent bony spike protrudes out of each of their elbows. The thorny, toothlike structures of their inner mouths somewhat resemble that of a leatherback turtle's. Additionally, they have long, prehensile triple-forked tongues that they can use to grab their prey.

Personality
Skullcrawlers are subterranean pack-hunting predators with insatiable appetites that are the results of their heightened metabolisms. They seem to have a mostly primal mindset. They are highly aggressive, as well as incredibly persistent in pursuing their prey. They do however show some degree of intelligence, shown when Skull Devil, the largest of the Skullcrawlers refuses to devour a grenade-armed Cole and simply swats him away.

The Skull Devil appeared to be more intelligent than the rest of his kind. This was seen when he appeared only once Kong was subdued by Preston Packard. It also seems to have a hint of sadism as he licks Kong's face maliciously after he's been tangled up in a Shipwreck's rudder chain during their battle. The Skull Devil was also shown to have a deep desire of killing and eating humans, which was shown several times when he diverted his attention from Kong to James Conrad and Mason Weaver, implying that he acts not only from primal instinct but some degree of malice and cruelty.

Kong: Skull Island
A Skullcrawler was first seen feasting on a dead Sker Buffalo by Kong. Kong was about to confront the creature when he was ambushed by a second Skullcrawler. After a lengthy battle, Kong ends up subduing and killing both Skullcrawlers by smashing one's skull with a devastating stomp and the other by stuffing its head into the ground, breaking its neck.

Another Skullcrawler ambushed Jack Chapman and a Spore Mantis, but went for Chapman and ate him alive while the Spore Mantis managed to escape. The same Skullcrawler then showed up in the boneyard and regurgitated Chapman's remains. When William Randa attempted to make his camera work, he was devoured by the Skullcrawler, who then tried to attack the group. Randa's camera started to flash inside the predator, which started to aggravate the monster.

The Skullcrawler then started chasing Mason Weaver, but the group retaliated using flamethrowers. The creature batted a crew member with its tail onto one of the Kong skulls, causing his backpack to detonate several canisters of toxic gas. The Skullcrawler started to grow relentless, and disturbed a flock of resting Leafwings which then turned their attention to attacking the group. James Conrad managed to killed some of the flying creatures using Hank Marlow's katana. The Skullcrawler then set its eyes on Conrad and Reg Slivko, but Weaver rescued them by tossing a lighter at one of the subterranean vents, creating an explosion that killed the Skullcrawler outright.

The Skull Devil, a giant Skullcrawler was awakened due to seismic explosives dropped onto Skull Island along with the rest of his kind. After Kong was incapacitated by Packard, Skull Devil let his presence be known by emerging out from the water. Thus began a three-part battle with Skull Devil having the upper hand on Kong initially. As he chased James Conrad and the other survivors of the research expedition sent to Skull Island, Earl Cole tried to sacrifice himself by arming several grenades before having the massive creature try to eat him. However, he didn't take the bait and batted him against the cliff as the grenades went off, killing him.

As the Skull Devil finally reached the rest of the crew, Kong appeared in time to stun it with a large boulder as the crew ran to safety.Skull Devil then turned his focus to Kong, pouncing on him and gripping his throat with his jaws. Kong and the Skull Devil continued to brutally wrestle, pummel and bite each other until the Skull Devil forced Kong into a shipwreck with a blow from his tail, where the ape became entangled in the chains. With Kong subdued in the wreck, Skull Devil returned his focus to the humans. As he approached the crew once more, Skull Devil's right eye was destroyed by a flare that Weaver fired, and this allowed Kong to use and swing the propellor of a wrecked ship at his adversary like a medieval flail, which caught the beast in the shoulder and allowed Kong to resume his fight with him.

During the battle, he was also fired upon by Conrad and his companions, allowing Kong to gain an advantage in the fight before finally uppercutting him with the ship's propeller, slicing the Skull Devil's throat wide open and seemingly killing him. As Kong saved Weaver, who had been knocked into the water earlier in the fight, Skull Devil pounced at Kong once more. After coiling his tail around Kong, he wrapped his tongue around the ape's arm, pulling it down his gullet in an attempt to devour Weaver. After a brief struggle, Kong tore the creature's internal organs out of his mouth, killing it outright.

Agility and Speed
Skullcrawlers can run very quickly despite having only two legs, and their speed matches or surpasses that of an adult human. They can also make quick turns as well.

Burrowing
Being subterranean in nature, Skullcrawlers are capable in using their limbs to burrow deep into the earth.

Durability and Stamina
Skullcrawlers are very durable, as they can withstand bullets from rifles and the searing heat of a flamethrower. The Alpha Skullcrawler was only dazed when Kong slammed his head with a boulder or smashed his face with a tree branch. They have incredible stamina, being able to stay in a full fledged fight for several minutes even whilst being incredibly injured.

Hunting
Skullcrawlers are both solitary and pack hunters. One can kill a Sker Buffalo on its own, and they can cooperate to take down more powerful creatures such as Kong.

Physical Strength and Combat
As the apex predators of Skull Island, Skullcrawlers are fearsome and deadly in battle, using their jaws full of razor-sharp teeth as their primary weapons. They can hold their own against opponents like Kong, able to withstand the blows and pummeling of the ape. Their serpent-like tails are used for swatting or for wrapping around an opponent during combat.

Prehensile Tail and Tongue
Skullcrawlers have prehensile tongues that they use to grab and quickly devour small prey, or for gripping large prey in combat. The tail is heavily muscled and extremely powerful, shown when the Alpha Skullcrawler lifted and flung Kong like a football across the lake with his tail. As stated before, the tail is also for wrapping around large prey, possibly to latch onto them for balance or to constrict them.

Heightened Metabolism
Skullcrawlers possess accelerated metabolism, which causes them to live in constant starvation. This is shown when Skull Devil ravenously tried to eat Weaver, and refused to let go of Kong's arm. Kong then turned his appetite against it, tearing out its tongue and other attached innards. (Had it opted to let go, it would have in fact survived, as Kong was holding Weaver and not its tongue.)

Fragile neck
Kong kills a young Skullcrawler by stomping on its neck, though the fully-grown Skull Devil is far more durable.

Tongue
It is shown that Kong can easily eviscerate Skullcrawlers by yanking out their tongues, which are connected to their internal organs.

Locomotion
Having only two limbs and walking on their front legs, their stance is rather unstable and easily toppled (when the Skull Devil is shot in the eye it clutches its eye in pain and almost falls over).

Vulnerable Eyes
The eyes of a Skullcrawler are one of its only weak points, as seen when Weaver destroys one of the Skull Devil's eyes with a flare gun. It is likely that the large eye-like sockets on the front of their faces serve as distractions from their real eyes which are set further back. They may also serve a function as heat-seeking pits.

Trivia

 * Skullcralwer stomachs don't appear to have the capacity to digest bone, as one is seen vomiting bones (including a human skull) in the graveyard, this is similar to some snakes which eat eggs.
 * Leapers from Dead Space share a similar body design to the Skullcrawlers
 * The Skullcrawlers' design have been influenced by the Two-Legged Lizard from the original 1933 King Kong film, along with Sachiel from Evangelion, No-Face from Spirited Away, and Cubone from Pokemon.
 * The Skullcrawlers combine features of snakes, lizards, and mosasaurs, all of which are members of the reptile order Squamata (it is possible that the Skullcrawlers are ancient, highly-specialized members of this taxon).
 * According to Hank Marlow they are the "Devils" of Skull Island and are feared by the natives to the point where they won't mention their true name, this makes "Skullcrawler" an alias or a nickname, as Marlow admitted he just "made up the name" to make them sound scarier.
 * In the novelization, it is stated that the Skullcrawlers are amphibious, as Weaver mentioned the one in the boneyard had gills.
 * This is similar to the MonsterVerse Godzilla, who also is a reptile but strangely possesses gills.
 * The Skullcrawlers are similar in appearance to the 'Mud Demons' from the third Chronicles of Riddick movie.
 * Given that no dinosaurs appear in the film, and that their remains are present in the Skullcrawlers' territory, it is possible that dinosaurs on Skull Island (if they were once present there) may have been wiped out by the creatures at some unknown point prior to the events of the film.

Films

 * Kong: Skull Island

Novels

 * Kong: Skull Island: The Official Novelization