Phantom ( The Spirits Within ) The Phantoms are ghosts of an aggressive , extraterrestrial race in " " . They are initially thought to be a race of alien invaders arriving on Earth via a meteorite known as the Leonid Meteor . Dr . Sid ' s research discovers the mass number of the Phantom populace remains constant ; a Phantom will reappear when killed . This is the result of the Phantom planet ' s Gaia , the Proto - Phantom . Profile . Appearance . Invisible to the naked eye , Phantoms can only be seen through the use of specialized bio - etheric equipment . The body of a Phantom can be charged by an external source , such as the flare - gun used by Aki , momentarily rendering it visible . Originally solid , their ghost - like bodies can pass through solid matter and if this matter is a living being , the Phantom will extract the being ' s soul and consume it . Behavior . The Phantoms are hostile , actively pursuing any living organism . Some intentionally emerge from the ground , walls or suddenly make themselves appear from thin air , like a typical ghost . Not all Phantoms remain invisible all the time . Although they hunt the living , they prey on ' souls ' , their vary touch dissolving a living person ' s soul via entire consumption or leaving the spirit to dissipate . They use their ' tentacles ' to remove a person ' s spirit , but sometimes use their body to come in contact with the prey without the need to ' pull ' it out . Even after receiving considerable damage ( such as from an explosion ) , Phantoms only disappear to re - emerge soon after when Proto - Phantom rebirths them . Types . Aggressive particles possibly originating from pieces of larger Phantoms , they can bury themselves into a host spirit and gradually consume it from within . The particles can be located , contained and destroyed thanks to technology developed by the Bio - Etherics institute run by Dr . Sid . In the case of Aki Ross , who has the particles contained , she sees see visions of the Phantoms ' homeworld that help her realize their nature . Standing at around three meters in height , these Phantoms are the type most commonly encountered . They possess a bio - organic , tentacle - like weapons on their arms that they wield like whips to ensnare or impale a victim . Large flying serpent - like predators , these phantoms possess tentacle - like appendages which they use to impale or entrap group - based victims and draw the prey to their mouths . Originally these Phantoms were created as bio - engineered tanks , but over time they grew wild and became part of the Phantom planet ' s ecosystem . Like the average Phantom , the Meta - Phantom possesses tentacle - like appendages over its body and a turret - like appendage on its back . It is difficult to kill with non - artillery weaponry . The Proto - Phantom is the what remained of the Phantom Planet ' s Gaia , thus all Phantoms killed off eventually return to the Proto - Phantom to be reborn . The Proto - Phantom originally resided within the Leonid Meteor . Story . When the Leonid Meteor fell on Earth and sudden worldwide deaths occurred , the blame was placed on a new type of virus . As thousands of plant and animal species perished , the natural cycle was disrupted . Dr . Sid and his team of researchers in the scientific institute of Bio Etherium revealed the existence of Phantoms , and thanks to the advancement of bio - etheric technology six years later , the United States Military Force ( USMF ) began its campaign against the Phantom invasion . Bio - etheric weapons were developed , and barrier cities were erected as defense against the invasion . Rather than an alien invasion force as first thought , the Phantoms are actually restless spirits of a long - dead world whose ability to consume the spirit of every living thing they touch makes them a threat to Earth . In life , the Phantom race used biological technologies used in war in the form of tentacle - like weaponry , animal - like machines and mollusk - like transports . In death their weapons carried over to the nether realm with them to be used against the living . Dr . Sid discovered that each spirit has a wave pattern . In studying the wave emitted by Phantoms , he discovered all Phantoms carry similar wave patterns . As two opposing bio - etheric waves cancel each other out when overlapped , he believed a wave pattern assembled from Earth ' s lifeforms may disable the alien Phantoms . The wave pattern must be assembled from different species , but due to the Phantom invasion , many living things have been obliterated . Dr . Sid studied the remaining lifeforms and discovered the wave may be assembled by gathering eight lifeforms that carry these waves , named Spirits . Assembling the wave patterns creates a perfect match to the alien Phantom ' s wave pattern to negate them . Aki Ross transmits the waves through Gray Edwards , her lover , who sacrifices his life to finish her and Dr . Sid ' s work . With the Proto - Phantom directly subjected to the wave pattern , all Phantoms are able to finally rest in peace . Other appearances . " Thriller " Easter Egg . Phantoms , including three alive - Phantoms , make an appearance ( along with the rest of the film ' s virtual cast ) in a hidden parody of Michael Jackson ' s " " music video created for the film ' s DVD release . The parody is set shortly after Douglas Hein inadvertently destroys the New York Barrier City ' s barrier control room . He runs runs into Aki , Gray , Ryan , Jane , Neil , Dr . Sid , Major Elliot and three alive Phantoms who proceed to , as a group , perform the dance number to " Thriller " with Aki as the lead .