Any of these roles might be in the game.

Townie: No special abilities.
Doctor: Can protect a person from being killed each night. Can only protect self once per game.
Careful Doctor:Can protect a person from being killed each night, however, can't protect a person twice, including self, for the whole game.
Bodyguard: Can guard a person at night. If somebody tries to kill that person... 50% chance the bodyguard will kill the attacker and the other 50% chance the bodyguard will die in place of the target. Can't target self.
Cop: Can investigate a person every night. In the day, will get results of whether the investigated was mafia or town sided.
Insane Cop: Can investigate a person every night, however, will always get wrong results (Will get guilty for innocent and viceversa). Isn't told that is insane. If killed or lynched, will appear as a normal cop.
Paranoid Cop: Can investigate a person every night, however, will always get guilty results. Isn't told that is paranoid. If killed or lynched, will appear as a normal cop.
Naive Cop: Can investigate a person every night, however, will always get innocent results. Isn't told that is naive. If killed or lynched, will appear as a normal cop.
Role Cop: Can investigate a person every night. In the day, will get results of what's the investigated's role.
Watcher: Can watch a person every night. Will know who visited that person that night. Won't know if the chosen person visited someone or not.
Careful Watcher: Can watch a person every night. Will know who visited that person that night, however, can't watch a person twice for the whole game. Won't know if the chosen person visited someone or not.
Tracker: Can follow a person every night. Will know who that person visited that night.
Hypnotist: Can choose a person every night. If that person targetted someone... 40% chance the effect will be targetted to someone else randomly and the other 60% chance the effect will go to the original target.
Illusionist: Can choose two people every non-consecutive night (if done in one night, the next night this can't be done). If the second person chosen tries to target the first person chosen, the effect is cancelled. Can't target self. If killed or lynched, will appear as a normal townie.
Mortician: Can uncover the role of a dead person each night. Mostly used in no-role-reveal setups.
Undertaker: Can target a person every night. If that person dies or is lynched, he will know the role. Mostly used in no-role-reveal setups.
Vigilante: Can kill a person every night. Mafia kills first, though.
Town Roleblocker: Can roleblock a person every night. Won't block other Town Roleblockers.
Greedy Roleblocker: Can choose a person every non-consecutive night. If that person targetted the Greedy Roleblocker, the person is roleblocked.
Solutionist: Can choose two people every night. If any of those people target the other one... 40% chance the effect will be cancelled, 40% chance the effect will be targetted to the Solutionist and the other 20% chance the effect will go on. Can't target self.
Miller: No special abilities. Appears as villager to self. Appears to be guilty. If lynched, will appear as a scum. If killed, will appear as a Miller. If investigated when dead, will appear as innocent.
Lie Detector: Can choose a post every night. In the day, will get results or whether the poster said the truth or a lie in that post. The Lie Detector's ability is lost if he reveals the other players, or they work out, what his ability is.
Grave Digger: No special abilities. Appears to be villager to self, which doesn't make much sense. Unless the janitor clears up the body or targetted by a role blocker, the Grave Digger will be seen as targeting any and all players that died during the previous night, by trackers and watchers.
Leader: No special abilities. If ever killed/lynched, votes will be anonymous for the next day.
Bulletproof: No special abilities. Can survive one kill. Does not apply to lynching.
Bomb: No special abilities. Anyone who kills the Bomb will be blown up. Will not explode if lynched.
Paranoid Gun Owner: No special abilities. Will shoot anyone who visits him during the night. Cannot die during the night.
Hunter: Can shoot a person if lynched.
Mason: No special abilities. Can communicate with other Masons at night.
Recruiting Mason: Can recruit a person every night. If recruiting an innocent person, player will be masoned. If recruiting a mafia or killer, Recruiting Mason dies. Will not overlap past power roles.
Dumb Recruiting Mason: Can choose a person every night. If recruiting an innocent person, player will be masoned. If recruiting a mafia or killer, Recruiting Mason dies. Will overlap past power roles.
Recruiting Mason Alpha: Can choose a person every night. If recruiting an innocent person, player will be masoned. If recruiting a mafia or killer, all Masons recruited die. Will not overlap past power roles.
Shrink: Can choose a person at night. That person can't be converted that night. Can only shrink self three times per game.
Jailkeeper: Can jail a person at night. A jailed person is protected, but prevented to perform any nightactions.
Oracle: Can choose a person each night. If oracle dies at anytime... The chosen person's role will be revealed to all. Jobs like this don't visit.
Dreamsender: Can choose two people each night. The 2nd person will receive the 1st person's role through a dream. Can't target self.
Gallis: No special abilities. Can only get lynched if the minority of the people vote for him, not including himself. Appears as villager to self.
Lightkeeper: No special abilities. If killed/lynched, people aren't allowed to talk and votes will be anonymous for the next day.
Beloved Princess: No special abilities. If killed/lynched, the next day phase is skipped (everyone is at her funeral) and can't vote nor talk.
Politician: Can steal a person's vote each night. Any time in the day, he can send a pm deciding on who he wants that person to vote for, until that is done atleast once, the person has his own vote.
Bus Driver: Can choose two people at night. Any actions done on those two people will be swapped. You have to choose either 2 or none. Can target self.
Cult Recruit: No special abilities. Can communicate with other Cult Members at night. If visited by a mason, will die. Wins by getting everyone not in the cult lynched.
Cultist: Can recruit someone at night. Recruited person becomes part of the cult. If recruiting an innocent person, player will be culted. If recruiting a mafia or killer, Cultist dies. If killed/lynched, nobody else can be recruited into the cult. Will overlap past power roles.
Cultist Alpha: Can recruit someone at night. Recruited person becomes part of the cult. If recruiting an innocent person, player will be culted. If recruiting a mafia or killer, all cult members die. If killed/lynched, all cult members die. Will overlap past power roles.
Fool: Can visit a person every night. Wins by getting lynched. (If the fool is lynched early, and doesn't end the game, commonly, the game continues)
Lyncher: No special abilities. Wins if Lynchee (told by pm who it is) is lynched and is still alive. You have to be in the members that voted the lynchee. If Lynchee dies, the Lyncher becomes a "Survivor". (If the Lyncher lynches the Lynchee early, and doesn't end the game, commonly, the game continues)
Lynchee: No special abilities. If lynched while Lyncher is alive and on the wagon (voting members), the Lyncher wins the game. Lynchees are commonly town-sided and aren't told they are a lynchee.
Serial Killer: Can kill a person every night. Wins if last man standing.
Survivor: Can hide behind a person each night, but only if that person is at home. Survivors who hide behind someone who is targetted will be targetted as well. Wins if living at the end of the game.
Warlock: Can choose a person each night. If that person is lynched by the village, the warlock has predicted correctly. Wins if predicts correctly two times.
Amnesiac: Can choose one person in the graveyard at night. Become's that person's role in the game the next day.
Mafioso: Can communicate with other fellow mafia members during the night. When decided, the mafioso who is going to kill the target has to send me who the target is. This doesn't happen if there is still a Godfather in the mafia.
Traitor: No special abilities. Does not participate in Mafia meetings. Mafia does not know who the traitor(s) is/are. Appears to be innocent.
Godfather: Can communicate with other fellow mafia members during the night. Sends who to kill and who does the kill when kill has been decided. Appears to be innocent.
Mafioso Usurper: A Mafioso that wants the Godfather killed. If all the mafia are killed, or the Godfather survives, then the Mafia Usurper looses. The other mafia don't know you are a Mafia Usurper. The mafia side has to win in order for the usurper to win.
Framer: Can frame a person every night. For that night, the target will appear guilty.
Hooker: Can kiss a person every night. Will roleblock that person for that night.
Yakuza: Can sacrifice self to convert somebody to mafia. Will overlap past power roles.
Disguiser: Can choose one person at night. If that person dies in the night, the disguiser will die instead, with the chosen's person role. The targetted player will also appear guilty for the rest of the game, and appear as a mafioso.
Janitor: Can choose one person at night. If that person dies, only the janitor will know the role of the target. Can only clean up the body twice per game.
Lawyer: Can choose one mafia every night. That mafia will appear innocent for that night.
Stalker: Can stalk one person at night. Will know that person's role in the morning.
Driver: Can choose two people at night. Any actions done on those two people will be swapped. You have to choose either 2 or none. Can target self.
Interceptor: Can follow a person each night. Will kill only one of whoever visits the same person. Anyone else who visits the same person finds out the identity of the interceptor.
Witch: Can place a curse on a person each night. That person will die... if visited by a person not sided with the mafia that night.
Dreameater: Can target someone every night. If that person received any dream, the Dreameater will receive it instead.
Spy: Can target one mafia every night. That mafia will appear as the chosen role by the spy (counters Role Cops and Dreamsenders).