List of extraterrestrial life in Alien Planet

This is a list of all aliens from the Discovery Channel show Alien Planet

Arrowtongue
The Arrowtongue is blind, so instead uses a sonar system to see. It has bioluminescent patches on its back it uses to scare off intruders. It has tentacle-like arms and a pair of large, two-toed, muscular legs. The Arrowtongue is called this due to a retractable appendage on its mouth that can attack prey, piercing the victim and injecting digestive juices into it. The insides of the prey is then turned to liquid; which it uses it's 8-metre (26 feet) long appendage to suck out it's food.

The Arrowtongue was the first fully-formed alien to be sighted by Leo and Ike, and performed a threat posture at the probes. It attempted to attack Leo with its tongue, and then turned its attention to a Gyrosprinter and chased it, but did not manage to kill it.

Gyrosprinter
The Gyropsrinter is a two-legged herbivore that gives it extremely flexible maneuverability. It has a skull-like head and bioluminescent patches on its back. Like the Arrowtongue, it has a tongue-like appendage used for eating.

The Gyrosprinter was first seen being pursued by the Arrowtongue, but escapes due to its agility. One was later seen being surrounded and cornered off by a pack of Prongheads, but escaped again.

Trunk sucker
Trunk suckers are relatively small, delicate creatures that are capable of gliding long distances. They feed on the tree sap from the plaque-bark tree, which is brought to the surface of the tree by daggerwrists. Trunk suckers use sharp claws to attach themselves to trees while feeding. They fly in small groups, rather like birds on Earth. They are also prey for the daggerwrist.

The trunksuckers were seen twice by Ike, the first time they were feeding ontree sap, and the second time their flock was attacked by a daggerwrist.

Unth
Unths are buffalo-like aliens with two large tusks facing forward on their faces. They are heavy yet lightly built, able to run long distances but still be a formidable herbivore. They are bipedal, and rather than create sound through lungs they have secondary air sacks on their flanks, which create a recognizable 'unth' sound.

The unths live on a large plain, which was explored by Leo first, before he was destroyed, and then Ike, who was searching for Leo.

Bladderhorn
Bladderhorns are aggressive creatures which live a solitary life in the mountain regions of Darwin IV. If a male bladderhorn encounters another, they will duel with each other by ramming heads and showing off their bioluminescent patches. They create a loud sound by using inflatable bladders on their flanks.

Leo was first to encounter Bladderhorns; he discovered two rutting. The sounds they were making were assumed to be communication by Leo, and showed it the Earth communication message. The bladderhorn simply stared at it and honked. Later Ike saw the bladderhorn briefly in his search for Leo.

Daggerwrist
Daggerwrists are aggressive, gliding aliens which live in the pocket forests of Darwin IV. It is built in a manner that is similar to a leopard, but is faster and can glide. It has a black, grim reaper type head and spikes on its back that can be raised and lowered. It preys on Trunk suckers, mainly to consume the sap they have digested first. This qualifies it as somewhat of apredator, though feeding on sap, it is technically a herbivore (tree sap counting as plants). It has a retractable feeding tube that can suck out its prey's body fluids. The daggerwrist has two scythe-like claws, which are used as weapons and for climbing. They sink so deep into trees that the sap bleeds to the surface, which in turn attract the trunk suckers.

Daggerwrists were seen twice. The first daggerwrist encounter ended with the daggerwrist attacking a camera disc launched by Ike. During the second time, Ike observed its feeding habits.

Groveback
Grovebacks are gigantic aliens five stories high. They are two-legged but have a rudder-like leg they use for balance that is dragged along behind them. They have a semi-circle shaped head and two enormous eyes. The Grovebacks bury themselves for long periods of time to feed on the nutrients in the soil. They have saplings growing on their back, which inject sugars into the creature. The Groveback gives the trees water in return.

Ike saw the Grovebacks twice. During the first time, he was studying the young saplings on its back, unaware that they were part of a creature. During the second time, it was attacked by a field of beach quills and died.

Littoralope
Littoralopes are small, numerous aliens that live throughout Darwin IV. There are armoured littoralopes,shown in alien planet,which use a 'two-headed' profile to confuse potential predators Wheras albino and green ones, shown in Expedition, do not have tails. The armoured littoralopes use a 'two-headed' profile to confuse potential predators. Their only real defense is to scatter in all directions, forcing predators to target one individual.

Littoralopes played little significance in Alien Planet. They took a role of running away, or prey for skewers.

Skewer
Skewers are huge jet-like predators that hunt using sonar. They hunt in small packs, using a lance protruding from its head. It uses this to disembowel prey and suck out its juices. Skewers maneuver by changing the shape of its wingspan. It propels itself by internally creating methane gas and then igniting it inside four pods, similar to those on modern-day jet-propelled aircraft. They are preyed on by eosapiens, and vice versa.

Skewers appeared several times in Alien Planet. Firstly, they were shown hunting Littoralopes. Shortly afterwards there was the explanation on the skewers flying, before it was knocked from the sky by an eosapien's spear. Lastly a skewer was about to kill Ike when another eosapien killed it and dragged it up a cliff.

Jetdarter/Beachquill
Jetdarters are the adult forms of beachquills, and are small flying scavengers that travel in small groups. They feed on the dead remains of any creatures another predator, such as a skewer, has not finished. It has been known to actively follow skewers for almost its entire 1-month life span.

Jetdarters only appear briefly - first feeding on the dead remains of a skewer's kill, and then flying through a field of electric mushrooms.

Beach quills are the larvae of Jetdarters, and are small, spike-like predators that are filled with neurotoxins. Beach quills live in huge groups, up to a million strong, and lie in wait for a creature to step by. When one does, the beach quills launch themselves into the hide of the prey in their hundreds. They then begin injecting the poison, which stuns the creature so the quills can burrow into it's flesh, where it cucoons itself and emerges as a jet-darter

The quills killed a groveback in the show, and did not appear a second time.

Pronghead
Prongheads are pack hunters with a similar lifestyle to that of a Velociraptor or pack hunting dinosaur. It stalks its prey from all directions and tries to surround it, working as a team. They kill their prey using prongs on their faces, which let out a feeding tube that inject digestive juices.

The prongheads only starred briefly in the show, attempting and failing to kill a Gyrosprinter.

Amoebic sea
The Amoebic sea is the remnant of an ocean that used to cover much of the planet. As Darwin IV's climate dried, single celled organisms that inhabited the sea adapted to the drastic change in oceanic volume by developing translucent membranes that trap the seawater. Its surface is similar to gelatin and cannot easily be penetrated. Despite its tranquil appearance, the sea can exhibit predatory behaviors. As observed by Ike as he was crossing the sea in search of Leo, it can extend parts of itself to catch low-flying sea strider nymphs.

Emperor Sea Strider
Sea striders are the largest creatures ever, both on Darwin IV and Earth. They walk over the Amoebic sea on which they feed by taking parts of it with them on their sucker-like feet. The striders have tentacles hanging from their face and large glowing holes in their head. The nymph-like young orbit the adult striders and are attracted to these holes. The young are also food for the sea, which extend tentacle-like columns to catch them.

When Ike is clinging on to a rock in a storm, he first sees the striders and their young. After the storm has passed, he tags along with them, as they are heading in the same direction that Ike is going to find Leo. He studies them on the way there.

Eosapien
Eosapiens are the most advanced life form on Darwin IV with the intelligence of early humans such as homo erectus. They float in mid-air by using two bags filled with methane gas. Eosapiens have long fingers that they use them to manipulate objects such as spears and create formations on the ground. They live in small tribes and hunt the other creatures on the planet. They hunt, and are hunted by, skewers.

From the very beginning, the eosapiens were spying on Leo and Ike. They observed them land in their shuttles, and every time either probe realized this the eosapiens intelligence made the probes unable to see them. The eosapiens destroyed Leo when he launched a camera disk, which they consider a threat. When he did this again to find his location, the eosapiens sabotaged him completely. On Ike's mission to find Leo, the eosapiens were watching him constantly, too. When Ike found them and showed them the Earth communication hologram they responded correctly and the eosapiens looked at Earth. Ike launched a camera disk to record the moment, but the eosapiens destroyed both the disk and Ike.