CREATURE FEATURE: Skullcrawlers

Skullcrawlers, also known as Cranium Reptant, are giant reptilian Kaiju that appeared in the 2017 MonsterVerse film, Kong: Skull Island.
Height : 3.65-28.95 meters
Length : 10-59 meters 
Mass : 40-100 tons​

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 invented by Marlow as he explained their history to Weaver and Conrad.

Appearance/Design
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 acting as heat-seeking sensory pits. The colors of their scales range from dark brown to dark green to a bone white color.

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.

Skullcrawler adolescents are easily distinguishable from adult skullcrawlers. Their heads are smaller, and more sloped than an adult. They also possess a more prominently brown skin tone. Adult skullcrawlers are larger, with most being as big as Kong. Their heads are more defined, larger, and somewhat angled.

The Skullcrawlers were designed to act as the "fallen angels" of Kong's kingdom and represent the darker, bleaker aspects of Skull Island.

Roar
The roar of the Skullcrawler is very high in tone, possessing a raspy quality with a hiss and growl mixed in between. According to supervisor sound designer/editor Al Nelson, the Skullcrawler roar was inspired by the pained squeal of a dying rabbit as well as the sounds of sea lions and squirrels. Some of its sounds were recycled from an Indominus rex from the 2015 film, Jurassic World.

Personality
Skullcrawlers are subterranean pack-hunting predators with insatiable appetites that are the results of their heightened metabolisms. They are highly aggressive, as well as incredibly persistent in pursuing their prey. They do however show some degree of intelligence, shown when the largest of the Skullcrawlers refuses to devour a grenade-armed Cole and simply swats him away. Adolescent Skullcrawlers appear to be naturally fearless, as two of them teamed up to attack Kong despite being smaller and out-muscled.

The largest of the Skullcrawlers 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. This large Skullcrawler 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. This could also hint that the skullcrawlers are innately malevolent.

Origins
Little is known about the origins of this voracious predator, although its evolutionary purpose is abundantly clear. The Skullcrawler exists to devour, destroy, and dominate. Subterranean in nature, burrowing up through the geologically unstable steam vents across Skull Island, it is as though the Skullcrawler climbed up out of Hell itself.

This terrifying serpentine is a hypervore: a creature with such a hyper-adrenalized metabolism that it exists in a constant state of starvation. Just as a shark must keep swimming to survive, the Skullcrawler must keep feeding, dislocating its own jawbone so to maximize its ability to swallow anything that crosses its path. And within that gaping maw exists a long, whiplash tongue, which the creature uses to ensnare and constrict its prey. Its olfactory system can sense hot-blooded life across huge distances. Once it has picked up your scent, the blood in your veins is like blood in the water!

Perhaps most striking is the beast's fearful visage. A chilling, lidless skull-face peers out through translucent flesh, as two dark and lifeless eye sockets regard their prey with cold, unflinching malice. The patterning of its facial features may be indicative of deimatic behavior designed to threaten and terrify its prey.

Given the unreachable depths of their subterranean nesting grounds, we have no way of knowing how big these things get, or the pecking order that governs their tribal feeding patterns.

The more we learn about the cultural history of Skull Island from the indigenous petroglyphs we have discovered, the clearer it becomes that the evolution of the Skullcrawlers has long been interwoven with Kong and his fallen ancestors. If Kong is god of Skull Island, then here comes the Devil!

History
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 one from behind. After a quick battle, Kong ends up subduing and killing both Skullcrawlers by stuffing one's head into the ground, breaking its neck, and smashing the other's skull with a devastating stomp.

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 vomited 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 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. Conrad managed to kill 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 Conrad's lighter at one of the subterranean vents, creating an explosion that killed the Skullcrawler on the spot.

The largest of all the Skullcrawlers was awakened due to seismic explosives dropped onto Skull Island along with the rest of his kind, and after Kong was incapacitated by Packard, he let his presence be known by emerging out from the water. Then he attacked the weakened Kong, quickly rendering the ape unconscious before turning his attention to the humans. As he chased Conrad and the other survivors of the research expedition sent to Skull Island, Earl Cole tried to sacrifice himself along with the beast by arming several grenades before having the massive creature try to eat him. However, the monster didn't fall for it, and batted him against a mountainside as the grenades went off, killing him.

As the large Skullcrawler finally reached the rest of the crew in a marsh, Kong appeared in time to stun it with a large boulder, enabling the crew to run to safety. The Skullcrawler then returned his focus to Kong, pouncing on him and gripping his throat with his jaws. Kong and the Skullcrawler continued to brutally wrestle, pummel, and bite each other until the Skullcrawler threw Kong into a shipwreck with his tail, where the ape became entangled in the chains. With Kong subdued in the wreck, the Skullcrawler was about to kill him when he's fired upon by Conrad and his companions. It then returned his focus to the humans and approached them, giving Kong the chance to free himself from the chains.

As he approached the crew once more, the monster's right eye was destroyed by a flare fired by Weaver, and Conrad lured him away from the crew on their boat. This allowed Kong to use and swing the propeller of a wrecked ship at his adversary like a medieval flail, which caught the beast in the shoulder and allowed Kong to pull the the Skullcrawler back toward him and resume their fight. Kong continued to wrestle the creature and threw him into the side of a cliff, causing Weaver to fall into the water below.

As the Skullcrawler continued to attack Kong, the ape uppercut him with the ship's propeller, slicing the monster's throat wide open and seemingly killing him. As Kong saved Weaver from drowning, the Skullcrawler 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 as she's clutched in Kong's hand. After a brief struggle, Kong tore out the creature's internal organs through his mouth, killing him instantly.
​
Skull Island: The Birth of Kong
The Skullcrawlers' history on Skull Island is revealed in Riccio's visions. Riccio says that the Skullcrawlers attempted to invade Skull Island and waged war against Kong's ancestors. When the Iwi first arrived on Skull Island, the Skullcrawlers had wiped out all but the two strongest apes, which turned out to be Kong's parents.

After the 1973 Monarch expedition, Skullcrawlers still inhabit Skull Island, but their population is controlled by Kong and none of them have grown to the size of the largest Skullcrawler. In another vision, Riccio explained that the Skullcrawlers continued their fight against Kong's parents.

One day, the Skullcrawlers attempted to kill Kong's mother while she was in labor but Kong's father kept them at bay. After Kong was born, his mother hid him in a cave and sealed it with rocks before she rushed to aid her mate. Kong then watched as the Skullcrawlers slaughtered his parents.

Abilities
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 of 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 largest of the Skullcrawlers 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.

Olfactory system
Much like snakes, the Skullcrawlers' olfactory system allow them to sense hot-blooded lifeforms from miles away.

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 a Skullcrawler lifted and flung Kong like a football across the marsh 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.

Strength
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.

Weaknesses
Heightened metabolism
Skullcrawlers possess accelerated metabolism, which causes them to live in constant starvation. This is shown when the largest Skullcrawler ravenously tried to eat Weaver, and refused to let go of Kong's arm. Kong then turned his insatiable appetite against him, tearing out his tongue and other attached organs.

Locomotion
Having only two limbs to walk on, their stance is rather unstable and can easily be toppled.

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

Vulnerable eyes
The eyes of a Skullcrawler are one of its only weak points, as seen when Weaver destroys one of the larger Skullcrawler'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

• The Skullcrawlers' stomachs don't appear to be able to digest bone, as one of them is seen vomiting bones, including a human skull, in the boneyard. This is similar to some species of snakes that eat eggs.
• 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, and would thus pose a threat to the world if they ever left Skull Island.
• This is similar to the MonsterVerse Godzilla, who also is a reptile but strangely possesses gills.
• The fact the Skullcrawler's eyesockets can be mistaken for their real eyes has a similiar fact for Orcas, as their white markings make people believe those are it's real eyes.
• The novelization states that Skullcrawlers can mimic human cries, and that this was the cause of Gunpei Ikari's death, as he and Marlow mistook one for an Iwi child crying. The book also suggests that the largest Skullcrawler appeared when it did because it somehow sensed that Kong was down.
• Skullcrawlers appear in the 2017 comic series Skull Island: The Birth of Kong. These comics are part of the MonsterVerse continuity. Currently, the creatures appear in Skull Island: The Birth of Kong #2 and Skull Island: The Birth of Kong #3.
• Skull Island: The Birth of Kong #2 has a cryptozoology entry for the Skullcrawler. The cryptozoological classification of the creature there is "Cranium Reptant". Much of the other information is unknown, although does mention their behavoir to be that of a destroyer and a hybervore.
• The Skullcrawler was originally going to be blind, using other methods to detect prey through something the director calls a "pit sensor". This detail is mentioned during director Jordan Vogt-Roberts' commentary found on the Kong: Skull Island DVD.
• During an interview with creature designer Zach Berger by Inverse, the designer notes that the director, Jordan Vogt-Roberts, became interested in the two-legged reptile creature that appears in the 1933 King Kong. This reptile is seen briefly after many of the crew are knocked off the log by Kong, as the two-legged creature is seen climbing the wall after this sequence. Berger states this reptile was what sparked the idea for the Skullcrawler as he notes that the reptile "had the two legs, which he was really gravitating towards, and it's kind of this long tail." Much more work went into creating a final look for the beast, including input from designer Simon Lee, although this marked the genesis for the new monster.
• Originally there was only one Skullcrawler in the script. This was expanded to featuring multiple individuals of the species, though. This detail is mentioned in the March edition of fxguide.
• Director Jordan Vogt-Roberts mentioned that at one time he wanted to call the Skullcrawler "MacArthur". The name, which he likened to the way someone names a pet a human name, would evoke people to ask why it was called that. The response would have been "it's like General [Douglas] MacArthur, can't stop him". This would have given the name a personal connection to Hank Marlow as well, who named it and had a World War II background. This fact is mentioned in Vogt-Roberts' commentary on the Kong: Skull Island DVD.