Psychonauts Wiki

The mind is the final frontier of humanity!

–Otto Mentallis

Otto Mentallis is a member of the Psychic Six. He still works for the Psychonauts as an engineering expert, producing and researching all sorts of technology to further the organizations' goals. He also runs a shop that sells psychic gadgets in return for Psitanium from his workshop located just outside the Motherlobe. For the sake of convenience, Otto-Matic terminals have been set up all over the place for other Psychonauts to make purchases remotely.


Otto has blue skin, gray hair, a large nose, and noticeable purple eyebags. He wears large square glasses with yellow rims. He sports a puffer jacket, the official psychonaut turtleneck uniform, and wears an eye-shaped pendant around his neck.


Otto Mentallis is generally sympathetic and reliable, seemingly enjoying nothing more than being of assistance to his fellow Psychonauts, despite the traumatic events he experienced in the past. He remains humble, but is not above a little bragging about his past exploits. Most of all, Otto loves engineering, going so far as to call his inventions nothing less than dreams, made reality through technology.

Conversely, the way Otto remains entirely functional after the Psychic Six' shared trauma and tends to prioritize technology over emotions—for example, his excitement at the thought of other Psychonauts' brains and even his own ending up in his Hall of Brains after their death—may occasionally make him appear somewhat morbid or uncompassionate. Compton, Bob, and Cassie all have mental versions of Otto that are less than understanding about their problems.


Otto was psychic scientist who teamed up with a man named Ford Cruller to study the psychic activity in an area called Green Needle Gulch. The two then discovered a mineral called Psitanium, and Otto used it to make psycho-reactive and psycho-enhancing devices. At some point, Otto met a woman named Lucrecia Mux, who fled from a war in her home country of Grulovia. He became fascinated by her Hydrokinesis, and hired her to help mine the Psitanium, as he believed it would speed up the process. He introduced her to Ford, and the two of them started dating.

Eventually, the group began experimenting with their psychic abilities, sometimes going so far as to experiment on themselves using a device called the Astralathe, a device designed to alter a person's psyche, in order to broaden their consciousness and knowledge of how their minds worked. After Lucrecia had her mental barriers weakened, war broke out in her home country of Grulovia, despite Ford's warnings, leaving the others to eventually be known as the Psychic Six.

This proved fatal, as they learned years later that Lucrecia's mind had become warped by the war into a genocidal monster known as Maligula. Otto and his friends were summoned by the international community to deal with her before she caused any more damage, in what would become the first mission for the organization that was later named the Psychonauts. However, the group refused to harm their former friend, and instead tried to reason with her. After Helmut Fullbear and Cassie O'Pia failed to talk her down, Otto then prepared to freeze the lake with a device called the Hyperhyglaciator, to try and render her powerless, while Bob Zanotto tried to restrain her with some vines. But Maligula broke free and tried to drown Bob. However, Helmut jumped in the way of the attack, causing him to get flung into the lake, just as the Hyperhyglaciator went off and froze all the water. Ford and Otto searched desperately to try and rescue Helmut, but he was so deep in the ice that they couldn't find him.

Eventually, Maligula was defeated. After the remaining members mourned Helmut, the Psychonauts were given their own base, known as the Motherlobe. Otto got most of the spotlight afterwards, shared only with Compton Boole, and for the most part, Otto was the only founding member walked from the Battle of Grulovia relatively normal, as every other member had some sort of tragedy happen to them. Otto then made many devices for the Psychonauts, using one called the "Defribu-lober" to hypnotize sixteen Trance Troopers at once while undercover.

At some point, Otto began collecting the brains of fallen agents and began experimenting on them to better understand the mind. One day, Otto was wandering through the Heptadome, the site where the Astralathe was kept, in the Green Needle Gulch, when he discovered a brain in a jar. When he scanned it, the brain was in a state of consciousness limbo, and couldn't tell whose brain it was. With no idea who the brain belonged to, Otto left it in his hall of brains as an unprocessed mind and labelled it as "Heptadome Harry".



Otto appears on a carved portrait in the Reception Area at Whispering Rock Psychic Summer Camp.

Psychonauts 2

Otto appears in various places throughout the game on his Otto-Matic terminals, but these are presumably only recordings. He physically appears for the first time in Sasha's Lab at the Motherlobe, offering to do more to assist Sasha in his interrogation of Dr. Loboto. In that moment, Razputin drops in on Sasha's Lab after being hazed by the other interns, still dressed only in his underwear. After Sasha gives Raz some new clothes, Raz formally gets to meet Otto, and excitedly brings up a flattering story from True Psychic Tales that seems to amuse the old Psychonaut. Otto then returns to his own lab.

After the mission at the Lady Luctopus Casino, Raz can exit the Motherlobe and visit Otto's lab for himself, where Otto gives him the Thought Tuner and Otto-Shot Camera to borrow, despite interns not strictly being allowed access to his inventions. At the lab, Raz also checks the Hall of Brains to obtain a "loaner brain" for Nick Johnsmith's brainless body, hoping to gain access to the Mailroom.

Otto doesn't make another appearance until the Astralathe is ready, after which he reunites with all of his old friends of the Psychic Six and works with them to try and lock Maligula away once and for all.

In the post-game, Otto can still be found back at his lab. He tells Raz that after their latest adventure, he's had the idea to build a range of tiny personal Astralathes to make small cosmetic personality changes.


  • Hydrokinesis: In Psychonauts 2, Ford mentions that the Psychic Six used the Astralathe to enhance their cryokinesis and hydrokinesis abilities.
  • Cryokinesis: In Psychonauts 2, Ford mentions that the Psychic Six used the Astralathe to enhance their cryokinesis and hydrokinesis abilities.
  • Time Bubble: Dr. Touch, a mental representation of Otto, can use Time Bubble.
  • Astral Projection: Otto is an expert in astral projection.
  • Levitation: Otto is shown using levitation while near the Astralathe in Psychonauts 2.


As the Psychonauts' lead engineer since their inception, Otto has built many different gadgets to assist on their missions. Some of his inventions, however, have no confirmed utility, and seem somewhat frivolous.

Otto's inventions include:


The name "Otto" derives from the Germanic word for "wealth".



Otto Mentallis is Gisu's mentor. She is also a gifted engineer, and works with him at his lab. Gisu respects Otto, but still passes on the assignment he gave her, to vent the Psychoseismometers around the Motherlobe, to Raz so she can focus on other things she deems more important.

Razputin Aquato

Otto is kind to Raz, and seems to encourage the young man's passion for the Psychonauts, telling him he's always welcome to try out some of the gadgets he's built, while Raz is as starstruck as he tends to be around all great Psychonauts of the past. Otto is also one of the few Psychonauts who seem to enjoy when Raz displays his encyclopedic knowledge of True Psychic Tales.

Ford Cruller

Ford is a colleague and fellow Psychic Six member, and a close friend of Otto's. The two of them were the first Psychonauts.

Compton Boole

Compton is Otto's friend, colleague, and fellow Psychic Six member. Compton, however, is terrified of Otto's judgement, due to how competent he is as a Psychonaut. One of the goat-handpuppet judges in Compton's Cookoff, Otto Meatallis, is directly based on his perception of Otto. Even so, Otto Meatallis is described as "the nice one" of the judges.

Cassie O'Pia

As a member of the Psychic Six, Cassie is a friend and former colleague of Otto's. Cassie's mind contains paper versions of the other members, which show that Cassie mostly remembers Otto as being rather emotionally dense and obsessed with his technology.

Bob Zanotto

Bob is a former colleague of Otto's, and the Psychic Six were clearly all friends, but whether Bob and Otto were all that close is debatable. Out of the entire group, only (a memory of) Otto can be found on an island in Bob's Bottles, saying that everyone only put up with Bob because he was a "package deal" with his husband Helmut, who everyone liked. Bob's mind also has figments of the group at his wedding, but Otto is conspicuously absent, the seat where he likely should be sitting instead filled by a teddy bear figment.

Helmut Fullbear

Helmut is a friend and former colleague of Otto's. Otto is seen enjoying Helmut's performance in a memory vault, and grieving at his funeral. Though no Otto figment is present in the version of Bob and Helmut's wedding in Bob's mind, Helmut's mind does have him present. Dr. Touch, a representation of Helmut's sense of touch in his mind, is also shaped like Otto, and has his voice.

Lucrecia Mux

Otto is the one who introduced Lucrecia to Ford Cruller, as the third member of the Psychic Six. They appear to have been friends up until the Battle of Grulovia. Despite the damage Lucrecia caused, Otto was willing to forgive her and help set things right.

Sasha Nein

Sasha is a colleague of Otto's. The two seem to get along quite well due to their mutual dedication to scientific progress.


  • Otto is never seen using psychic powers directly in Psychonauts 2, and even when he works with the other members of the Psychic Six to power the Astralathe, the psychic energy is channeled through his pendant instead of coming from his brain.
  • Otto is the only member of the Psychic Six whose mental world Razputin does not visit in Psychonauts 2, simply because he is far more well-adjusted than the others and the need never arises to take a look into his mind.
  • The letters in the Cruller's Correspondence section of Ford's Mind that are addressed to Otto list his location as "Research and Development, Motherlobe Industries, Inc."
  • Otto was the one who cut the ribbon for the Motherlobe's opening ceremony, as seen in a picture on the "History of Psychonauts" board.
  • Otto's hallmark, appearing on several of his inventions, seems to be a color spectrum that goes from red to a blueish purple. It may be a reference to the colors invisible to the human eye, from infrared to ultraviolet.
  • When Raz uses Clairvoyance on Otto, he appears as a brain in a jar, perhaps showing that Otto is more focused on the science behind the brain than the personality of its owner.
  • According to Hollis, Otto is quite partial to imported truffles. Hollis herself thinks they are an unnecessary expense.


Concept art and Promotional Materials


Art assets

Psychonauts 2

Textures and Model Screenshots