* CompleteMonster: The Titan [[BigBad Cronus]], when released from his prison in Tartarus (where he was imprisoned for being an evil tyrant and for trying to [[OffingTheOffspring kill his kids]]), wastes no time in seeking to resume his dominance over the world and all in it. With nothing but hatred for his children and the other Gods, Cronus is utterly brutal and merciless in his tactics, which include [[ColdBloodedTorture torturing]] and [[AbusiveParents trying to kill his own children]] while throwing the world into chaos and disarray. Cronus eventually gets tired of the human heroes resisting him and makes it a point to attempt to [[KillAllHumans exterminate the entire human race]] in retribution. At other points, Cronus releases the [[SavageWolves savage werewolf]] Lycaon from imprisonment to eat "whomever he may please" and tries to get his [[AlmightyMom mother Gaea]] to kill Zeus for him. [[FauxAffablyEvil Sophisticated, suave, seemingly polite]] and never at loss for a vicious plan, Cronus repeatedly proves how nothing will stand in the way of his goals of domination and destruction.
* MostAnnoyingSound: During their expedition to Atlantis, Neil frequently says "Ping!" for no other discernible reason than that it annoys Archie half to death.
* TrueNeutral: The Oracle. In the pilot, Cronus tries to say that the Oracle works for him, but the Oracle tersely reminds him that "I work for ''everyone''." Throughout the series he proves this, providing information not only for Cronus but also for the seven heroes, of whom he seems to be rather fond.
** Also Thanatos, the god of death, whose purpose is very simple: to collect the deceased. He is neither good nor evil, and will obey only whoever wears the Helmet of Darkness.
* UncannyValley: In one episode, Odie devises a computer program that simulates Cronus. Hephaestus builds a robot to utilize the program for training, but the resemblance to the actual Cronus terrifies Theresa. [[spoiler:With good reason, as it turns out.]]