Doctor Nastidious is the antagonist of the Test Subject series, appearing in the Test Subject games Test Subject Green and Test Subject Complete. He also appears in the background of several levels of Test Subject Arena and as a playable character in Test Subject Arena 2.

Doctor Nastidious is a green skinned scientist who is much like an evil version of the Professor, responsible for raiding Xeno Industries and performing tests with the Professor's equipment in his (Dr. Nastidious's) own base.


Doctor Nastidious appears as a cylindrical green skinned man whose head appears oval shaped when seen from the font and hemispherical when seen in an angle other than the front. His face is coloured in many shades of green, his face appearing as several squiggly lines of varying size that appear in a darker shade of green at the edge of his face, but become significantly lighter as they move in.

Doctor Nastidious has two small light green circles for cheeks, and a short wavy line where his mouth would presumably be. He usually wears two circular objects over his eyes, these presumably being glasses of some sort. Behind these, Doctor Nastidious's eyes are two vertical rectangles with a smooth lined top and bottom. Doctor Nastidious wears a hat similar to a Fedora.

Doctor Nastidious has a cylindrical body with regular sized arms and wears black/brown gloves and brown shoes, and wears a robe of some sort in his Test Subject Complete sprite.

Incorrect portrayals

Art that depicts Doctor Nastidious has generally not been consistent, as there have been variations in depictions of Nastidious's body below his head. It is possible that Nastidious's design was changed between games. The walking sprite - and possibly standing sprite - for Doctor Nastidious in Test Subject Green depicts him without any arms and wearing a jacket instead of a robe-like garment.


Doctor Nastidious's full walking sprite in Test Subject Green

Mimicked Profs

Mimicked Doctor Nastidious in TSA

Test Subject Complete icon

On the logo of TSC

It is likely this was done because only the area of his sprite around his head is supposed to be seen, as such, no detail needed to be put in below this as the player wouldn't see it, and in order to see the full sprite other third party programs are required. Along with this, he seems to be wearing a one button jacket.

In Test Subject Arena, Nastidious appears more fat, have a forehead that is a tiny bit larger than his Test Subject Complete art, and a head that is also a tiny bit bigger. Notably, he is depicted with a large arm and short, large legs, where his Test Subject Complete sprite do not even show his legs, only his feet. However, these discrepancies are likely attributed to the mimic green enzyme not being completely accurate in transformations.

Finally, the logo for Test Subject Complete depicts Nastidious with a hand that has only four fingers, and also skin that is not green, although it is likely his skin is not green due to the nearby flames, and that his hand had only four fingers because it would have been hard to fit in five.

Game information

Test Subject Green


Break in at Xeno Industries

Doctor Nastidious had found out about the scientist's tests at Xeno Industries. He sent people to watch the Professor, resulting in the Professor increasing security. One day, the Doctor (who was possibly with troops) stormed Xeno Industries and headed to the Professor lab. As the Professor injected Test Subject Blue into Test 3, the Doctor broke into the scientist's lab, setting off the lab's security alarm. A bag was thrown over the Professor's head and he was dragged down and beaten up.

After Blue completed Test 3, the Professor used the last of his strength to inject Blue into Test 4, before getting dragged away, either unconscious or dead. Nastidious grabbed Blue after he reached the food pill at the end of the test. Nastidious took Blue to his own lab to do his own tests. He apparently did some sort of economic damage to Xeno Industries, has in his first level prologue he describes how Xeno Industries (called "lab") is "history".


Nastidious placed Blue in his test chamber, testing Blue against his own inventions and other types of green enzymes. The Doctor would frequently walk by the test chamber and type something on his PDA, take off his hat, take off his glasses, wipe his glasses, or just watch.

Once Blue had completed test 30, the Doctor placed blue in Rex209.
Return to Xeno Industries

Doctor Nastidious spent a total of nine days going to Xeno Industires and coming back to his base. He was looking for Blue's entire formula, as what he had was incomplete. He destroyed Xeno Industries when he did not find it.

After that, it is not known what he did, but it is likely he assisted in the creation of the giant Proto mech suits. Presumably after learning of the Professor coming back to life (possibly from The Machine), he increased the security around his base, placing mercenaries that waited for the Professor to come so they could kill him.

For some reason, he waited in front of the door to a special room of his, and once the Professor got to him, he retreated into his room. As the Professor had followed him into his room, The Machine transformed into a war machine of some sort and fell down in front of Nastidious, which caused Nastidious to leap into him and commence battle with the Professor.

Unfortunately for Nastidious, the Professor exploited the weak point of The Machine and destroyed it, causing The Machine to throw Nastidious out of it, and throw him on to the ground on to his stomach as Nastidous let out a groan. Seconds after this happened, Nastidious turned over on to his back, breathing heavily, and activated a self destruct mechanism in an attempt to kill the Professor.

With the self destruct mechanism going off and destroying his base, it is presumed Doctor Nastidious was killed.

In game

Test Subject Green

The Doctor will act much like the Professor, coming over and watching the chamber, typing things on his PDA, cleaning his glasses, and taking off his hat. Unlike the Professor, mercenaries armed with guns are seen in the background.

Test Subject Arena

The doctor appears in levels which do not take place at Xeno Industries. He does everything he does during normal gameplay of Test Subject Green in level 5-20. If the mimic green enzyme (player two) is left idle long enough, he will mimic the Professor if the level is set in Xeno Industries, and Nastidous if in a level not set in Xeno Industries. The mimicked person looks like a small green version of the Doctor.

Test Subject Complete
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Test Subject Complete - Level 30

Doctor Nastidious in level 30

Prior to level 29, Doctor Nastidious is mentioned in a few messages and appears in the background of level 1 an 2. He appears in person on level 29, waiting at the end of the level, and on level 30. Level 30 takes place in a room that is likely Nastidious's special room, as it included a picture of him up on the wall.

As the Professor enters, The Machine will drop from the ceiling on to the form and shift around a few parts, turning into a different machine. Nastidious will then jump into him and the battle will start.
The Machine will first try to crush the player with its drill, but it will step back to take some speed. Avoid it by using the teleporter next to the professor, which leads him above the machine making it crash to the wall. Then, shoot the red ball. Every time this is done, a mercenary will come, which the player must destroy before concentrating on destroying The Machine.

When the mercenary is killed, hide to the right side under the teleporter to avoid The Machine's laser attack. When it have stopped, go under the machine and it will drop down. Dodge it to the left and shoot the ball. Hitting it a third time is simple: get behind The Machine, when it starts to move around the stage, by using the teleporters.

When the professor is behind the machine, duck and shoot the soldier to make sure the professor does not get hit by laser. The machine makes one to five rounds around the stage. Before that, avoid the laser. When The Machine has done the one to five rounds, go under it, dodge to the right and avoid its drill attack by using the teleporter next to the professor.
Post battle
After The Machine is destroyed, it will fling Nastidious out as it explodes. Nastidous will let out a groan and fall on the floor, on his stomach. He will quickly turn over on to his back and begin breathing heavily. After this, he will lift up his hand and press a button, and begin laughing.

Test Subject Arena 2

Dr. Nastidious appears in Test Subject Arena 2 as a playable character. He was first seen in a preview image for the game. In the game he uses a pistol to fire bullets at opponents. The bullets are similar to the bullets fired by Mercenaries but do not travel as fast as their bullets do. His melee attack is a medium wide kick in front of him.

When idling (as a result from the player not touching any of the controls for a while) he will take out his fedora and place it on his head. As he does this, his cloak swishes about him a bit. He will stand there with his hat on for a few seconds and then take it off. If the player moves while he is wearing the hat, the hat will disappear.

Nastidious is capable of firing a long stream of bullets without irregular stops.

Upon completing his single player course, the following quote from his is provided: "With this victory I am one step closer to world domination!", this quote referencing his intended world domination in Test Subject Complete.

Bump Battle Royale

Doctor Nastidious appears on the Test Subject stage, drawn on to a piece of paper with Nastidious' plans also written on it, these plans having relation to the Test Subject series' plot. Also on the paper is a picture of the Professor dead and Nastidious cheering.


At the start of each level in Test Subject Green, Doctor Nastidious's PDA will appear onscreen, which will read words which are probably his report or his observations.

Level 5
Day 5:-

At last, the Enzymes are all mine! I have waited a long time for this. That weak old Scientist and his stupid lab is history.

Now I will take it to the next level and realise the true potential of this so called Test Subject Blue.

Level 6
Day 6:-

Wheres the fun in testing Blue against Green? Lets make things interesting!

Lasers should do the trick, deadly and indestructible! Now lets throw in a untested Greeny. I like this one, hes got style!

Level 7
Day 7:-

Ok ok... So Blue managed to work out the last puzzle, I wont be so easy on Blue from now on.

Lets see if these new Changeable Reflectors cause problems!

More Quotes

Other appearances


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  • Doctor Nastidious's name is only seen on a door in the ending of Test Subject Green and the opening of Test Subject Complete (which is the ending of Test Subject Green).
  • When Doctor Nastidious puts Blue in the Proto-Suit/Rex209, he wears gloves similar to the scientist's gloves but his sleeves are dark blue.
  • Doctor Nastidious reappears in Test Subject Arena, only he does not make a canonical appearance, as Test Subject Arena is a spin off and not part of Test Subject Blue history.
  • Doctor Nastidious is shaped like a pill.
  • Doctor Nastidious is possibly a reference to Darth Sidious from Star Wars, and his guards a reference to Stormtroopers.
    • Doctor Nastidious's name may also be a portmanteau of nasty and hideous, insidious, or fastidious.
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In his special room where the boss battle occurs, there is a map marking some European, African, and Asian countries, these being Algeria, Italy, Greece, the Czech Republic, and Turkey. As mentioned by Rex-209 about Dr Nastidious' world domination, these countries were most likely to have been his first targets.