* AntiHero: Type V.
* DarkIsNotEvil: At least nowhere near as evil as you'd expect him to be, especially compared to Thomas.
* DeadpanSnarker
* EvenEvilHasStandards
* GreenEyedMonster: The Professor often notes (to the point of it being a catchphrase) that Satan torments humans because he wants to bring everyone down to his level- he hates himself and his situation and wants everyone to be as miserable as he is. For extra points, Satan is actually described as having green eyes.
* {{Hypocrite}}: One of the main reasons for his hatred of humans is their refusal to own up to their mistakes, yet he continually objects to any attempt to blame him for his own rebellion against God and subsequent banishment from Heaven.
* KaleidoscopeEyes: At one point when Satan is losing his temper, the Professor notes that his eyes have gone purple; then, a little later, [[BlackEyesOfEvil completely black]].
* KickTheSonOfABitch: Most of the punishment he inflicts upon Thomas would be disgusting, but given how Thomas is a monster it's hilarious. Case in point: trapping him under an incontinent hippo for most of an episode before he eventually removes it... [[CrowningMomentOfFunny only to dump an incontinent and heavier rhino in its place]]. The rhino then tramples him before it goes off.
* LouisCypher: We always know who he is, we just don't know who he's pretending to be.
* NobleDemon
* PaperThinDisguise: He may be able to change his shape, but humorously, doesn't do much (or often anything) to change his voice.
* PayEvilUntoEvil
* PetTheDog: Every now and then.
* {{Satan}}
* WouldntHurtAChild: Satan has strict standards of not possessing anyone who isn't old enough to make moral choices, and is thus in one episode is shown to be [[EvenEvilHasStandards enraged]] at fundamentalists who believe a child is possessed by him, and want to beat Satan out of the child.

* TheAtoner: Averted. The Professor, and then Scumspawn, spends a lot of time trying to reform Thomas. He doesn't really get it.
* ButtMonkey: Satan's personal punching bag, particularly because [[EvenEvilHasStandards Thomas disgusts even him]].
* TheCasanova: In life, he was pretty successful at seducing women.
* CorruptCorporateExecutive: Was one when alive.
* EvilRedhead: Stated to be red-headed in series six.
* FauxAffablyEvil: Thomas is [[Series/TheNewStatesman Alan B'stard]] on steroids.
* {{Flanderization}}: To an extent. In the first series, he's more of a malevolent cad, but later episodes present him as a rage-filled psychopath. Weirdly, this happens at the same time as efforts are made to reform him.
* NeverMyFault:
** After marrying Edith's daughter, he tormented her to the point of insanity. He eventually accepts 3% of the responsibility for the marriage's failure, which Scumspawn notes is 3% more than last time.
** In another episode, Thomas argues that his being in Hell is unfair as his evil acts were predetermined as part of God's plan. After God tells him that God's plan doesn't exist and everything he did was out of his own free will. He then says that [[InsaneTrollLogic it's still God's fault for being stupid enough to give people like him free will.]]
* NotSoHarmlessVillain: He's more of a punching bag than a villain by the time of the series. However, in life, he murdered, raped, and tortured god knows how many innocent people, and was able to get away with it completely until [[AlwaysABiggerFish Satan found out about it.]]
* PetTheDog: [[spoiler: literally, in season 7]].
* UpperClassTwit: A particularly malevolent one.
* AnythingThatMoves: Has sexual feelings for cartoon characters and mannequins. [[HaveIMentionedIAmHeterosexualToday As long as they're female, of course.]]

* ButtMonkey
* TheStarscream

* AmbiguouslyGay: For Satan. He's a bad chooser.
* BumblingSidekick
* MinionWithAnFInEvil
* MoralityPet: For Thomas in later seasons.
* GeniusDitz: Arguably. He is a totally naive and incompetent, but is secretly an incredibly talented musician and artist. At one point, he is able to BUILD ROBOTS.
* ChasteHero: His love for his master is totally non-sexual. [[BarbieDollAnatomy Then again]], it kind of has to be.
* ExtremeDoormat: He once ate himself because Satan told him to.
* TokenGoodTeammate: The only good demon.

'''The Professor'''
* FlatEarthAtheist
* MoralityPet: Essentially is this for Satan.
* WideEyedIdealist: His idealism is shattered only once during all seven seasons of torment. [[MomentOfAwesome He gets over it.]]
* StraightMan
* TokenGoodTeammate: The only non-evil character in the main cast until Scumspawn appears.
* WorthyOpponent

* Jerkass
* AttentionWhore

* SuspiciouslySimilarSubstitute: [[spoiler: introduced after the Professor leaves and plays a similar role.]] Played with in that there are notable differences between the two characters; where [[spoiler:the Professor's idealism]] comes from trying to find the bright side of every situation, Edith's comes more from romanticizing certain people, ideas, and events while seeing no good in others. Also, while [[spoiler:The Professor]] came to be fairly well-liked even by the villains, Edith is tolerated at best by most of the other characters.
* StraightMan
* CoolOldLady
* {{Determinator}}: As Satan notes 'arguing with her is like... well it's like cornering a badger'.

'''Jane Austen'''
* AxCrazy
* ShroudedInMyth: She's absolutely nothing like you'd expect from her work, or even from historical accounts.

'''Adolf Hitler'''
* NeverMyFault: He maintains that the Holocaust was merely overreacting to being filmed in the shower, and he blames his failed invasion of Russia on Jesse Owens.
* UltimateEvil: He's the most frequently mentioned out of all the historical figures, but he never speaks, is never spoken to, and other than one scene where he is explicitly in disguise, is never even spoken about in such a way that one can infer his presence.