This page contains a list of the creatures apprearing in Lost in Space.
Angus[]
Angus was the uncle of Hamish in the episode "The Astral Traveler;" as with his nephew, he was condemned to haunt the living in punishment for his misdeeds. He is finally released from his curse and is able to enter a more peaceful afterlife with Hamish.
Anti-Matter Monster[]
The anti-matter monster appears in a scene in "The Anti-Matter Man" where the caged John Robinson provokes the anti-matter Don.
Bog Monster[]
The bog monster was the denizen of a radioactive swamp that was disturbed by Dr. Smith’s careless blasting in the episode "Ghost in Space;" naturally invisible, Smith believes it was the ghost of his late Uncle Thaddeus.
Bolix’s Creatures[]
Bolix’s creatures were two large, hairy bipeds in the episode "All that glitters." The performed the rôle of bloodhounds for the law officer in his pursuit of the thief Ohan, and were his 'muscle' during his subsequent investigation.
Bush Creature[]
The bush creature was encountered by Dr. Smith and Will after their 'space raft' landed back on Priplanus in their attempt to reach earth in the episode "The Raft." It is apparently a plant, and was killed by John Robinson when it had Will and Dr. Smith trapped.
Cosmic Monster[]
The cosmic monster was a fearsome creature in Dr. Marvello’s space circus. Vicho, the circus' strongman, wrestled with it as part of his act. Dr. Marvello has some sort of control over the monster. When Marvello attempted to kidnap Will, the creature attacked John Robinson to prevent him from reaching his son.
Cyclops[]
The cyclops were a species of creatures of gigantic size inhabiting Priplanus. The crew of the Jupiter 2 encountered several near their campsite on the planet. They were easily killed by laser fire.
Fly Creature[]
The fly creature was native to the asteroid which the Saticons attempted to present as Earth to Dr. Smith, Penny, and Will. When Smith and the children returned from the asteroid, the fly creature somehow accompanied them, giving Dr. Smith a bad fright.
Giant Bird Creature[]
A giant bird was the companion of Tiabo on the planet in Sector 6.30. It was used by Tiabo in an attempt to terrorize the Robinsons into leaving. It had a collar around its neck and Tiabo usually used a lead attached to the collar when he appeared with the bird.
Giant Debbie[]
Giant Debbie was the bloop grown to several times normal size after eating a fruit containing bacteria that caused abnormal growth. Her personality did not seem to change and she remained playful and affectionate.
Gog[]
Gog, along with Magog, was one of the guardians of the cave of the Dranconians. He and his companion were chained to pillars to prevent access to the most secluded part of the cavern.
Hades Monster[]
The monster was one of the beasts in the inter-dimensional, hades-like realm in which Morbus had been imprisoned. When Don is about to shoot the creature, Morbus stops him, saying that the monster is useful in keeping down vermin, and cites Dr. Smith as an example.
Hairy Creature[]
The hairy creature was a beast of Priplanus lured to one of the Keeper’s cages shortly after Dr. Smith was imprisoned. His arrival prevents Will from rescuing Dr. Smith.
Hairy Monster[]
The hairy monster was the creature killed when Dr. Smith panicked and threw Thor’s hammer at it in the episode "The Space Vikings." This action summoned Brynhilda to the planet.
Horned Mutant[]
The horned mutant was a creature dwelling in a sand-filled crater; it may have been a mutation connected in some way with a recent meteor shower or it may have arrived with the meteor shower. It was very dangerous and repeatedly stalked the Robinsons.
Invisibo[]
Invisibo was an invisible, poisonous creature which John Robinson was forced to fight in the episode "Hunter's Moon." The Professor was able to defeat it by using a smoke screen generated by the Robot to show the creature’s location.
Magog[]
Magog, like Gog, was one of the guardians of the cave of the Dranconians found chained to a pillar within the cave in the episode "Cave of the Wizards."
Mirror Monster[]
The mirror monster was a creature inhabiting the interdimensional world existing behind mirrors. Although it was dangerous and actively sought the boy behind the mirror out, the Boy himself made a game of provoking it to relieve his boredom. It was notable for having a single eye on a long stalk.
Moss Monster[]
The moss monster was a creature that menaced Verda, Penny and Will while out on a nature walk. Its location was know from its tracks, and Prof. Robinson had issued a warning for the crew to stay clear of the area. Wishing to frighten Verda into leaving, Dr. Smith suggested that she take the children to that area on a nature walk.
Mummy[]
The mummy was one of the guardians in the cave of the Dranconians in the episode "Cave of the Wizards." It was the creature that drew the hypnotized Dr. Smith deeper and deeper into the cave, inviting him with a beckoning motion.
Pit Monster[]
The pit monster was a creature that inhabited a deep chasm into which Will and Judy fell while fleeing Tybo. Will held it off with a machete while Judy attempted to climb out of the pit.
Plant Creature[]
The plant creature was the mutated development of a houseplant smuggled aboard the Jupiter 2 by Dr. Smith. It was mutated by cosmic radiation and grew to human proportions.
Plant Creature 2[]
A second plant creature was the clone of the first plant creature. It was created when the Sobram warrior using a hyperlaser beam on it. The energy apparently triggered the reproduction of the original plant by parthenogenesis.
Quano’s Beast[]
Quano's beast was the target of Quano’s solo hunt. He was spurred on by his desire to emulate his father who had defeated another monster as a boy himself.
Ruby Eating Creature[]
The ruby eating creature gathered and stored rubies on which it fed after the manner of a squirrel.
Small Plant Creature[]
The small plant creature was the first stage in the mutation of a plant Dr. Smith smuggled aboard the Jupiter 2. After being bathed in cosmic rays, it grew much larger and fixated on Dr. Smith as its mother.
Spike Monster[]
The spike monster was one of the illusory creatures created by the alien machine to intimidate Will Robinson in “Flight into the Future.” Will is able to overcome the illusion by his force of will.
Spirit of Space[]
The spirit of space was the animated statue of Dr. Smith. It was brought to life when cosmonium spilled on it, then pursued Dr. Smith in order to acquire more.
Stone Men[]
The stone men were two illusory creatures created by the alien machine to intimidate Will Robinson in “Flight into the Future.” Knowing the creatures were only illusions, Will forced them to disappear.
Wind-up Monster[]
The wind-up monster was one of O. M.’s creations in the episode "The Toymaker." The Toymaker sent the creature to track down and capture Dr. Smith and Will.
Wooden Soldier[]
The wooden soldier was one of O. M.’s toys that was sent to stop Will from searching for Dr. Smith.