Ghostfreak

Ghostfreak is an Ectonurite originating from the planet Anur Phaetos.

Appearance
Ghostfreak is a shadowy, ghost-like alien, and his body can change intangible at will. This enables him to phase through anything and turn invisible at will. He may have only one eye, but he can position it anywhere on his body, but by using a track traced along his skin. His appearance can also bring fear in the hearts of others ,sometimes, even Ben is creeped out. Ghostfreak can also peel back his own skin, which reveals a horrifying mass of tentacles, which is seen in The Big Tick and Last Laugh. Direct sunlight and chemicals that can affect his body will nullify his invisibility and intangibility. He is a last resort method.

Ghostfreak's fully developed form is truly more menacing than the Omnitrix form. He actually has a skull head, and it's upside down. His tentacles, hidden underneath the first form, are revealed. Spikes grew on his shoulders and through one half of his arms. In this form, Ghostfreak now has claws instead of hands. The skin he had in his Omnitrix form is presumably a safety feature incorporated by the Omnitrix's creator, Azmuth, both to safeguard this alien from exposure to sunlight and to lessen the frightful impact of its true hideous appearance. This is substantiated by the fact that Ghostfreak willingly ripped it off, despite it being bright daylight at the time, in order to reveal his true appearance; the true nature of this skin, however, is never fully explained in the series beyond its sun-shielding capabilities.

Powers and Abilities
Ghostfreak can also peel back his own skin, which reveals his horrifying true form. Direct light and chemicals that can affect his body will nullify his invisibility and intangibility. He is also meant for extreme combat with his second layer of skin. He was removed from the Omnitrix when he escaped because Ectonurites have the miraculous ability to possess life from a single strand of DNA. He was trapped inside of the Omnitrix again before he was incinerated by Ben in Be Afraid of the Dark. If Ben is in this form for more than ten minutes, then Ghostfreak's personality might take over which is unlikely. Ectonurites are perhaps the most frightening creatures in the galaxy. With an exposed and upside-down skull for a head, only one eye, gray-blue skin (light gray in the original series), exposed bones on certain parts of their bodies, and white talons (black in the original series). They can also possess people for limited periods of time.

Ectonurites also have powerful psychic abilities such as telepathy and telekinesis (Ghostfreak used telekinesis in the episode Ghost Town while he was fighting Vilgax). Ghostfreak can shoot a purple or blue beam from his chest (when he pulls back his skin) and from his hands. This ability was confirmed in the episode Be Afraid of the Dark when Benvicktor and Ghostfreak locked beams in the vacuum of space.

While wearing his second skin, Ghostfreak can move his eye across black lines that cover his body, as shown in Hunted.

Weaknesses
Direct exposure to sunlight can greatly harm and might even kill Ghostfreak without the second layer of skin (or a human host).This weakness is the result of Zs'Skayr removing his protective second layer of skin after being separated from Ben. Ghostfreak's death happens when Ben opened the roof of a space ship when in space so the light of the sun shined onto Ghostfreak, killing him. Certain substances can also neutralize his phasing ability and his invisibility.

Ben 10: Alien Force
Ghostfreak reappeared in the Alien Force episode Ghost Town. He was kept in solar prison after being separated from Ben. Vilgax freed him to get the information about the location of Primus. After being freed he attacked Vilgax and conquered Vilgaxia (Vilgax's home planet) and turned citizens into Ghostfreak's minions (whom resemble Ghostfreak's original form from the first series). Vilgax ran off to get help from Ben and Ben helped him. During the battle with Ghostfreak they were easily outmatched by him but when Ghostfreak tried to control Vilgax, Ben leaped in and Ghostfreak's DNA is added into the Codon Stream, allowing Ben to transform into Ghostfreak, only before Ghostfreak quickly regained control of Ben. But with the help of Vilgax, Ben took control and transformed back. Ben still has Ghostfreak and can use it.

Ben 10: Ultimate Alien
He is now back in his sun-shielded form, instead of gray he is now the color white and the lines across his body have been rearranged. He also has a larger green eye now and most likely doesn't have the spirit of Zs'Skayr inside him anymore. He also has pointed fingers

Ben 10

 * Permanent Retirement (first appearance)
 * Hunted
 * Kevin 11
 * Last Laugh
 * Secrets x2
 * The Big Tick
 * Ghostfreaked Out (Selected alien was Heatblast)

Ben 10: Alien Force

 * Ghost Town (first re-appearance)

Trivia

 * Ben got him back in the Omnitrix in the original series. However, a continuity plot hole in Alien Force indicates that Ben may have lost him again then gained him back again.
 * He is one of 2 characters that Zombozo is scared of. The other one is Anodite Gwen in Hit 'Em Where They Live.
 * Ghostfreak shares many traits with Big Chill and AmpFibian such as intangibility and invisibility, and at one point Ben had no control over them (though, Ghostfreak escaped the codon stream while Big Chill was pregnant, and AmpFibian was worried about being captured by Aggregor).
 * When giving background information on Ghostfreak, his creators said that before they started drawing prototypes, they decided that they wanted to make something like a Genie. As time went on the however, idea and character design eventually evolved into a ghost. A hint of the original design can be seen in Ghostfreak's tail.
 * Ghostfreak's origin within the Omnitrix seems to be in question; in the series, he says he passed on his consciousness through a single strand of DNA, while the "pop-up" facts shown during several marathons indicate that he rode the Florauna DNA when it was collected in order to get into the Omnitrix.
 * Ghostfreak is the only character that has his head upside down.
 * He is one of the eleven Omnitrix/Ultimatrix aliens whose source alien is known by name, and out of two that were usable before Ultimate Alien. The others are Benwolf, Benmummy, Benvicktor, Nanomech, Chromastone, Ampfibian, Water Hazard, NRG, Terraspin, Armodrillo.