Monster Guide

 Learn how to survive a possible encounter with a graboid, shrieker or an assblaster when visiting Perfection Valley.
 These texts have all been taken from the Monster Guide originally published on SciFi.com/tremors in 2002. That website is long gone, but it can still be accesed via the Internet Archive. We assumed it would be more convenient to just have all of it right here, on one easily accessible page.

Graboids hatch from eggs which can lay dormant for as long as 300 years, and possibly even longer. Abnormal heating (geothermal or radiation) of the soil around a Graboid egg can accelerate its gestation and cause it to hatch sooner.

Once hatched, Graboid worms grow very swiftly into 30-foot-long, sightless, underground eating machines that hunt via their extra-sensitive hearing. They can zero in unerringly on the slightest movement or vibration. It's also worth noting that many people who have survived encounters with Graboids have reported that one can smell the stench of a Graboid long before one actually sees its eel-like hunting appendages.

SAFETY TIP: When in an area infested with Graboids, it is important to remain absolutely motionless and silent. If you are in a stopped motor vehicle, do not let the engine idle, and be certain to turn off car stereos and any other sound-producing devices, such as portable CD or tape players with headphones.

El Blanco

Every year, countless tourists pass through Perfection Valley, hoping to catch a glimpse of its most elusive underground denizen, El Blanco, a.k.a. "The Great White Graboid."

A sterile albino Graboid, El Blanco poses no risk of metamorphosing into deadly Shriekers. Consequently, El Blanco enjoys protection under U.S. federal law as an endangered species. All of Perfection Valley has been declared his habitat — a kind of Precambrian wild-animal park.

That's not to say El Blanco is harmless, however. He has a talent for destroying cars, buildings and anything that wanders out into the desert. Fortunately, he is usually content to graze on wild animals such as coyotes. He sometimes treats himself to some of the local ranchers' domesticated cattle or sheep, but because he must negotiate a narrow canyon filled with "shallow alluvials" in order to reach the ranchers' plateau, such forays are infrequent. El Blanco can't travel through bedrock, so as the layers of loose soil get thinner, he becomes like a whale beached in shallow water. Strays who wander off the plateau, however, are fair game.

When he's eaten a lot, El Blanco sometimes semi-hibernates in the far north end of the valley, giving the locals a temporary break.

The mutual safety of El Blanco and the people of Perfection is overseen by Agent W.D. Twitchell, U.S. Department of the Interior. He's responsible for ensuring El Blanco's survival, as well as that of the local human population. If Twitchell decides life with El Blanco is too dangerous for either side, he has the authority to condemn the valley and evict the residents.

Naturally, Twitchell keeps a close eye on Melvin Plug, who has more than once expressed a desire to rid the valley of El Blanco. If El Blanco were to become history, the valley's federally protected status would end, permitting Melvin to pursue his opportunistic real-estate schemes.

After an indeterminate time spent living underground, a Graboid surfaces and undergoes a gory metamorphosis: It divides into three to six Shriekers — fast-moving, lion-sized bipeds.

Though Shriekers, like Graboids, are technically blind, they can track their prey by sensing infrared radiation. They are especially sensitive to temperatures between 97 and 107 degrees F. — the normal range for mammalian body heat.

These extremely dangerous creatures reproduce hermaphroditically — in effect, each Shrieker is "born" pregnant. Shriekers' ability to reproduce is limited only by their access to food. Once a Shrieker has eaten enough food, it disgorges a new, ravenously hungry Shrieker. Consequently, it is crucial that Shriekers be prevented from getting to plentiful food.

Shriekers' prolific reproductive skills make them so dangerous that the U.S. government has decreed they are not a protected species, and should be killed on sight.

SAFETY TIP: If you encounter a Shrieker in the wild, do anything possible to mask your body heat. Thermally insulated blankets are effective camouflage against a Shrieker's infrared senses, but be certain to cover yourself entirely. Your exhaled breath can be a fatal giveaway if the ambient temperature differs from your body's internal temperature.

Approximately 24 to 72 hours after being spawned, depending on numerous variables, Shriekers metamorphose into winged creatures that Perfection businesswoman Jodi Chang has nicknamed AssBlasters.

AssBlasters are so named because they launch themselves into flight by igniting an explosive mixture of liquids produced in their bodies; they blast off like rockets, then glide for up to several miles. They cannot fly like birds.

Like Shriekers, AssBlasters hunt via infrared radiation and are voracious. Also like Shriekers, AssBlasters are considered extremely dangerous and are not protected by law. They should be killed on sight.

An AssBlaster is "born" with a single Graboid egg in its abdomen. It is thought that an AssBlaster's evolutionary goal is to carry its egg as far as possible, to ensure the spread of the species. This, however, is only a theory.

Very little else is known about AssBlasters or Shriekers. One AssBlaster currently lives in captivity in Las Vegas, the property of Siegfried and Roy, who are underwriting research on the creature. It was sold to them by Nancy Sterngood and her teen-age daughter, Mindy, who captured it.

SAFETY TIP: If an AssBlaster is encountered in the wild, it is possible to conceal oneself by masking one's body heat (see the safety tip regarding Shriekers). Another important note is that, unlike Shriekers, AssBlasters do not multiply. If they eat to excess, they will enter a state that survival expert Burt Gummer calls "food coma." If you are unable to mask your body heat from an AssBlaster, attempt instead to sate its hunger with high-calorie foodstuffs until such time as it becomes dormant.

Graboids are extremely ancient (Precambrian) lifeforms. They date to a time when it was thought no vertebrate life existed on Earth.

Rare throughout history, they were almost never captured in the fossil record. Kate White discovered the only known Graboid fossil. Rhonda LeBeck has now earned her Ph.D. and is the world's foremost authority on living Graboids. She sometimes returns to Perfection to study El Blanco.

The life cycle of the Graboids currently appears to be as follows:

1. A Graboid egg lays dormant for up to three centuries, or possibly even far longer.
   
   
2. A single Graboid worm hatches from each egg. The newborn Graboid eats all manner of organic material and grows rapidly.
   
   
3. When the Graboid reaches maturity, it metamorphoses into approximately three to six bipedal Shriekers.
   
   
4. Shriekers reproduce hermaphroditically. Their ability to reproduce is limited only by their food supply. Their cycle of reproduction is very short, often being measured in hours.
   
   
5. Approximately 24 to 72 hours after spawning (during which, depending on food supply, an indeterminate number of parthenogenic reproductive cycles might have occurred) Shriekers metamorphose into AssBlasters. Each AssBlaster carries within its torso a single fertilized Graboid egg.
   
   
6. At some stage not yet observed or understood, an AssBlaster buries its Graboid egg in the Earth for gestation. It is unknown how long an AssBlaster can survive after relinquishing its Graboid egg.
   

Science now recognizes that there probably are eggs of this ancient but extremely rare lifeform buried all over the world, as evidenced by the Graboid appearances in Mexico and Argentina. Like the coelacanth, the animals simply went unrecorded throughout history.

Until now....