This is getting serious!
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Mental (also known as Tah-Um or Chaad Sheen) is the main antagonist of the Serious Sam series. Mental is the last of the Hum-Tah (the Infinite Ones), a species of god-like beings that once ruled over galaxies. 


It is suggested that Mental wipes the galaxy clean of intelligent life once every one hundred thousand years. In between these cycles of war, he enters the state of hibernation and supposedly leaves autonomous machines (mostly around homeworlds of extinct species) on guard, watching out for any activity in the galaxy.

Mental utilizes both technology and magic in order to achieve his goals. The diversity can be seen in his army, where he uses cyborgs, executed enemy soldiers raised from the dead, spaceships, biological weapons, reanimated skeletons of long extinct races, clones, creatures made out of pure magic, robots, trained war mammals, mercenaries, and even plain vehicles. These creatures are sent in very large numbers, which is possibly why Mental always manages to defeat any species he encounters.

He also recruits primitive races in order to bolster his ranks. He has established agreements with creatures such as the Aludran Reptiloids in order for them to work for him, and has even tampered with the evolutionary paths of some creatures so he can mold them into troops for his own purposes. He uses several methods to coerce races into working with him. In the case of the Aludran Reptiloids, he offered them magical combat abilities. In other cases, such as the Zorgs, he simply paid for or hired massive amounts of disposable troops.

This isn't to say that Mental has no intelligent creatures working with him, however. Ugh-Zan III and Ugh-Zan IV appear to be intelligent enough to serve as admirals in Mental's army, and Mordekai the Summoner was intelligent enough to properly use and research magic. These are most likely exceptions.


Mental's true name is unknown, there are also two other alias.

"Mental" was a name bestowed by humanity because of how chaotic and insane his army is. However, his home is indeed called "Mental Residence" by his daughter in BFE and "Mental Institution" in SS2.

"Chaad Sheen" ("wizard exterminator" in Sirian) was a name bestowed by the Sirians before they were wiped out by his armies.

"Tah-Um" ("The One Infinite" in Eillian) was a name bestowed by Eillians and is believed to be Mental's original name, as a Gnaar says that Tah-Um is going to "moon" Sam to him in Serious Sam 3: BFE.


Mental's appearance is unknown. One can speculate that his appearance is somewhat hinted by logos seen on some of his army's vehicles or creatures, where he's depicted as a Cthulhu-like creature (as seen in Serious Sam 2).

Mental's hand appears in the Next Encounter, but this game has been qualified as non-canon by Croteam[1], hinting that it must not be taken into consideration.  

Origins and prehistoryEdit

Mental is the last of the Hum-Tah, or the Infinite Ones, extremely powerful entities of unknown nature, who ruled over intergalactic empires for eons. First mentions of their existence come from the ancient race of Eillians, who discovered ruins of long forgotten civilizations:

"Of the infinite, there are three kinds:
Lost ones, they are lost in infinity
And useless.
Ones that create, they were our gods
They were finited.
Ones that destroy, they were banished.
But The One Infinite is still.

This ancient message hints that the Hum-Tah, with the exception of one, are all extinct or banished from our universe.

Tah-Um ("Tah-Um" was a name bestowed by the Eillians and is believed to be Mental's original name) being the only surviving Hum-Tah in the galaxy was slowly driven insane by loneliness and developed deep hatred and jealousy towards the younger races as they were able to escape the terrible fate that befell the Hum-Tah.

It is unknown when Tah-Um started his genocidal campaign to wipe out all sentient life in the galaxy, but it is believed that he has been doing this for thousands, if not for millions of years.

Allegedly, soon after this discovery Eillians were spotted and exterminated by Tah-Um. Hundred thousand years after, the Sirians suffered the same fate when they discovered traces of those who came before them.

Battle with SiriusEdit

Many, many years after the fall of the Ellians, the Sirians appeared and helped more primitive species, such as the Kleers. During their travels, the Sirians stumbled upon ruins of ancient Eillian civilization. Soon after, they translated their old song about the Hum-Tah, revealing the danger that Mental poses. At the same time, coincidentally or not, Chaad Sheen ("Chaad Sheen" was a name bestowed by the Sirians) found Sirians, too.

Mental began waging war against them, resurrecting and recruiting their fallen soldiers as members of his army. Soon enough, it had wiped out all of Sirius and its colonies, including firebombing the Kleers and reanimating their skeletons. Unknown to Mental was that Sirians had one more of its search parties out in the universe, which resided on Earth. These Sirians had left much of their technology and warnings about Mental to the Earthlings.

After wiping out the Sirians, Mental hid back in unknown areas of space, leaving an array of autonomous machines around Sirius, disguised as an asteroid field, for the purpose of alarming Chaad Sheen should any intelligent life appear.

Humans discover MentalEdit

Around two thousand years later, humans discovered old Sirian technology buried under old Ancient Egyptian ruins. After some reverse-engineering, humans obtained ways to travel between stars with ease. An exploratory force lead by Captain Sam Stone was sent to chart out the remains of Sirius for a corporation. However, there was something unusual; the planet was surrounded by an asteroid bubble not mentioned in the records. Sam, pressured by the corporations, examined one of the asteroids, revealing hidden alien machinery and thus triggering the alarm system, bringing Mental back one hundred years earlier than usual.


Serious Sam 3: BFEEdit

By the time Serious Sam 3: BFE has started, it is clear that humanity has lost. All humans in Cairo had been wiped out by Mental, and it seems that all that was left was a small group of Earth Defense Force soldiers posted somewhat near Cairo. The humans had placed their last hope on the Time-Lock, which was something that Mental seemed to be unaware of.

During Serious Sam's journey to power up the time-lock, Mental staged a final attack on the Earth Defense Force's HQ, which effectively wiped them out. Now that the last bit of resistance had been wiped out, Mental prepared to drop the Moon towards Earth in order to blow Earth up. Sam, however, fought towards the time-lock, hoping to get in there to give humans one last chance. Mental attempted to stall Sam long enough so that he could be crushed by the Moon by sending in huge amounts of aliens and even Ugh-Zan IV, one of his trusted subordinates, but Sam managed to defeat them. As Sam headed towards the Time-Lock, he decided to call Mental and threaten him, but instead, he gets Mental's daughter, Judy. After a brief chit-chat, she told Sam about her dad blowing up Earth with the Moon. Right afterwards, Sam saw the Moon hurtling towards the Earth, so he quickly ran into the Time-Lock right before the Moon hit and blew up Earth. In this timeline, Mental managed to finish off humanity, just like all the other species that encountered him.

Serious Sam: The First EncounterEdit

After Sam enters the time-lock, he warps back to Ancient Egypt. As expected, the time-lock alerts Mental from that time period that there is intelligent life on Earth, so he sends some of his forces to slaughter humans back then. This Mental is unaware of Sam's abilities at first, and sends only weak forces at him. However, after Sam slaughters them, he begins sending in more and stronger forces, such as the Highlander Aludran Reptiloid, against him. Sam still manages to slaughter every creature that Mental sends at him.

Knowing that something major is up, he sends Ugh-Zan III at Sam while he is approaching the Great Pyramid. Sam manages to retreat to the Great Pyramid and reach its top where the ship is parked. Ugh-Zan III scales the pyramid in order to finish off Sam, but Sam manages to manipulate the ship's security system to defeat Ugh-Zan III. After Ugh-Zan III is slain, Sam boards the ship and calls up Mental, who is not at home at the moment.

Serious Sam: The Second EncounterEdit

By the time Sam crash-lands on Earth again, Mental is well aware of Sam's abilities and tries to stop him with stronger and newer forces from the start. He seems to be somewhat aware of Sam's plan to get a backup ship, as he does things such as installing an Exotech Larva in front of the portal to medieval Europe. He even manages to steal the Holy Grail, which is used to activate the backup Sirian ship Sam is looking for. However, he is unable to use or destroy it because he nor his creatures are authorized to use it, as they are evil and therefore are not within God's mercy. Sam manages to defeat the Holy Grail's guardian, Mordekai the Summoner, and uses it to activate the ship. Before he leaves, he calls up Mental and mocks him by pretending to apologize for killing his monsters and troops, then he tells Mental he is going to get him.

Serious Sam 2Edit

When Sam is warped to the last of the Sirians' home, he is informed that Mental has one large weakness; a medallion. However, the parts have been scattered throughout the galaxy in order to prevent anyone from using it against him. Armed with this knowledge, Sam sets out to get each of the pieces and remake the medallion.

After clearing out Mental's forces from several planets, he finally makes the Medallion and intends to use it on Mental. Sam managed to pierce the defense shield on Sirius just long enough to enter Sirius, where he did battle against Mental's forces on his home turf. After many battles on Sirius, Sam managed to find Mental's base, the Mental Instititution. After fighting off many enemies, including the base itself, Sam finally managed to get to Mental and finish him off once and for all. However, little did Sam know that Mental was already preparing to leave and sent a decoy voicebox in a dark room to distract Sam long enough so that he can escape. By the time Sam discovered the decoy, Mental was already leaving Sirius and heading out to another part of space.

As an end of credits blooper during after Sam retrieves the whole medallion from Ellenier, Sam returned to the Sirian's home and informed them about having the medallion. While talking to them, he noticed a large supply of boxes with individual medallions in the room. Sam learned that the medallion actually did nothing and that there were plenty of them. Angered, he chases the Sirians around the room wanting some payback.

According to his voicebox, it's hinted that he is Sam's father. However, it's unknown whether this is true or not. Judging by Sam's inhuman fighting ability against Mental's army and generals, it's likely true.

Serious Sam: Next EncounterEdit


Mental as he appears sitting on his throne in Serious Sam: Next Encounter.

Mental makes a brief appearance at the start of the game where he tells the evil Serious Sam Clone that he shouldn't get into trouble nor mess with Mental's Time-Lock. During the scene, his hand can be seen; However, Croteam stated on Reddit that this game is not canon, so this is not an reliable element regarding his appearance.[1]

Otherwise, the main antagonist is the Evil Serious Sam Clone, although NETRISCA's entries constantly mention that Mental has been involved with the new and old creatures Sam faces in the game.

Serious Sam: Double DEdit

According to Serious Sam and NETRISCA at the start of the game, Mental has been defeated. However, after exploring Ancient Egypt again, NETRISCA starts to see that something strange is happening, as Mental's forces and crystal beacons made by him have been found. More crystal beacons and monsters are found in two other time periods, suggesting that Mental is still planning to wipe out intelligent life. By the end of the game, it is highly suggested that Mental is still alive, and that Sam's fight with Mental was actually him vacationing and turning off NETRISCA during it. The presence of one of Mental's generals, General Maxilla, suggests that Mental is still active.

Serious Sam: The Random EncounterEdit

Humans are getting tired of hunting down Mental in the past, so they send Serious Sam and a few pals of his to kill Mental in the future. However, Mental appears to be aware of this, as he sends hordes of monsters towards them, and tricks Sam and friends to going into a large pyramid, where Ugh-Zan is waiting to kill them after solving a switch puzzle in it. After killing Ugh-Zan, Sam and friends strike a cool pose and return to the present, disappointed that Mental was not in the future. Where and when he is, is never told.

Behind the scenesEdit

Mental was supposed to be a brain in a jar, with tubes coming out of it.

List of appearancesEdit


  1. 1.0 1.1