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

Contents: Top · 0–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Amoebic Sea[]

Amoebic sea

Size: That of Texas, USA
(around 680,000 km2 (260,000 sq mi)*).
Diet: Predator/Photosynthetic
Prey: Sea Strider Nymph

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. When Ike studied a change in the surface texture, the Amoebic Sea attempts to attack Ike. It does this again when it devoures a Sea Strider nymph.


Size: 2.5 m (8.2 ft) high, roughly 4 m (13 ft) long(Film narration says "Roughly the size of A T-Rex," but it is actually much smaller.)
Habitat: Circumglobal
Diet: Gyrosprinter, littoralope, prismalope, and symet
Specific hunted creatures: gyrospinter,littoralope

The Arrowtongue uses a sonar system to terrify prey. 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 are then turned to liquid, which it uses its 8 m (26 ft) long appendage to suck out as food.

The Arrowtongue was the second fully-formed alien to be sighted by Leo and Ike, and performed a threat posture at the probes. Due to Leo's programming, the Arrowtongue nearly caused Leo to go offline, twice, once with its tail, and the other with its tongue.



Size: 10 cm (3.9 in) tall
Habitat: Littoral Zone
Diet: Predator
Prey: Various

Beach Quills 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 its flesh, where it later emerges and reburies itself.

The Quills killed a Groveback in the show, making it suffer a slow, painful death.


Size: 1.4 m (4.6 ft) in height
Habitat: Mountains
Diet: Herbivore

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.

Leo was first to encounter Bladderhorns; he discovered two rutting. The sounds created by the Bladderhorns are produced by putting air in bladders, then releasing it. When Ike found one of the Bladderhorns that Leo discovered, he watched it for a moment, then it retreated at the sight of a skewer.



Size: Roughly 1.8 m (5.9 ft) long
Habitat: Pocket Forests
Diet: Omnivore
Prey: Trunksucker

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, it can glide, and has a somewhat reptilian appearance. 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 an omnivore (tree sap counting as plants and the Trunk Suckers as animals). 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.


Emperor Sea Strider[]

Sea Strider
Size: Roughly 23 m (75 ft)
Habitat/Diet: Amoebic sea

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.


Size: 9 m (30 ft) tall
Habitat: Circumglobal
Diet: Omnivore
Prey: Various

Eosapiens are the most advanced life form on Darwin IV with the intelligence of early hominids such as Homo erectus. They float in mid-air by using two bags filled with methane gas. Eosapiens have long fingers that they use 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 are one of Darwin IV's apex predators, and they both hunt on 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 movement, 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 shut him down 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 presumably Ike.



Size: Roughly 15-18 meters (50-60 feet/five-six stories) high
Habitat: Littoral Zone
Diet: Soil

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 semicircular-shaped head and two enormous nostrils. 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, one was attacked by a field of beach quills and died.


Size: 1.9 m (6.2 ft) high at the hip
Habitat: Plains, Littoral Zone
Diet: Herbivore

The Gyropsrinter is a two-legged herbivore with 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.



Size: 50 cm (20 in) long
Habitat: Plains, Littoral Zone, Pocket Forests, Mountains
Diet: leftovers of skewers and other predators

JetDarters are small red flying creatures. They feed on the dead remains of any creatures killed by another predator, such as a skewer, that has not been finished.

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



Size: 3 m (9.8 ft) high at hip, 6 m (20 ft) long
Habitat: Plains, Littoral Zone
Diet: Herbivore

Littoralopes are small, numerous aliens that live throughout Darwin IV. There are armored Littoralopes, shown in alien planet, which use a 'two-headed' profile to confuse potential predators. Albino and green varieties, shown in Expedition, do not have tails. 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.



Size: Roughly 2.2 m (7.2 ft) high at shoulder
Habitat: Littoral Zone
Diet: Predator
Prey: Gyrosprinters, Littoralopes

Prongheads are pack hunters with a similar lifestyle to that of a Velociraptor or a Wolf. 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.



Size: 15 m (49 ft) wingspan
Habitat: Circumglobal
Diet: Predator
Specific hunted creatures: littoralopes and eosapiens

Skewers are huge jet-like predators that hunt using sonar. They hunt in small packs, using lances protruding from their heads. They use these lances to catch prey and suck out the juices. Skewers maneuver by changing the shape of their wings. They propel themselves by internally creating methane gas and then igniting it inside four pods, similar to those on modern-day jet-propelled aircraft. They prey, and are preyed on by Eosapiens.

Skewers appeared several times in Alien Planet. First, they were shown hunting Littoralopes. Shortly afterwards there was the explanation of a skewer's flight, before it was knocked from the sky by an Eosapien's spear. Last, a Skewer was about to kill Ike when another Eosapien killed it and dragged it up a cliff.


Trunk sucker[]

Trunk sucker
Size: Roughly 1 m (3.3 ft) long
Habitat: Pocket Forests
Diet: Tree Sap

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 on tree sap, and the second time their flock was attacked by a Daggerwrist.



Size: 2.5 m (8.2 ft) in height
Habitat: Mountains
Diet: Herbivore

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 by Ike, who was searching for Leo.

See also[]

  • Expedition (book)
  • Alien Planet
  • Darwin IV