Mummy: The ResurrectionEdit
For the mummies, Apophis is the core of all the world's woes, the ultimate incarnation of Isfret. Since time began, Apophis has been around, defiling and destroying the tenets of Ma'at. It is the ultimate trickster, the overwhelming darkness and the unceasing perversion, that plagues the world. Among the minions of Isis and Osiris, Apophis is considered the source of all evil, and their champions are commanded to fight against the Serpent whenever they can. Mummies see rage, selfishness and despair as symptoms of Apophis' influence and will strive to undo this harm, restoring Ma'at in the process.
Many are drawn into the Great Serpent's snare unwittingly as their natural desires for success and wealth grow slowly tainted by Apophis' insidious influence and are turned against them. The Great Serpent, despite being not afraid of engaging its enemies in outright conflict, is skilled at using subtlety to achieve its goals and is able to convert even it's enemies into its tools.
The Amenti believe that Apophis rests beneath the Underworld, and that Great Maelstroms are the result of the Great Serpent trying to rise from beneath the Well of the Void. The end of the world will come when Apophis manages to rise through Oblivion to reach the world of flesh.
Likewise, its minions are corruption incarnate, perverting the innocent and defiling the unspoiled. They are referred to as the "Faces of Apophis". Sutekh was the Corrupter's mightiest champion, slaying Osiris and battling Horus through the march of years and his children, the Followers of Set, continue to do Set's and Apophis' biding. Other servants of the Serpent are the Bane Mummies and the weaker Asekh-Sen, who filled with its essence and bound to fulfill its will. Unclean spirits of all sorts in both the Underworld and the spiritual are seen as minions of Apophis. Amkhat cults that celebrate cannibalism openly worship the Serpent.
Vampire: The MasqueradeEdit
Vampires are seen as servants of the Corrupter, even if they are not aware of it. Still, some Mummies, in their long existence, have crossed ways with vampires that sought to follow the basic tenets of Balance and maintain their Humanity in the face of the horrible things they have to do. Some, like the Disciples of Anubis, have been loyal allies to Osiris and opposed the Corrupter in multiple ways.
Followers of SetEdit
The relationship between Apophis and the vampires that are the get of his once greatest champion, Sutekh, is stressed. The servants of Ma’at often claim that all vampires serve Apophis in one way or another, whether they know it or not. The Followers of Set themselves are somewhat divided in that matter: While the Hierophants and Methuselahs of the Clan have employed servants of the Corrupter on various occaisons, such as the Bane Mummies, they have no control over them and these vile beings can also turn against those who have called them. With the arrival of the Sixth Maelstrom, the Bane Mummies have seceded from the Followers of Set and both sides have begun to scheme against each other extensively.
The Followers of Set continue to battle against Ma’at, but they do it out of a gnostic faith that tells that the material world is a prison and the order of the Cosmic Principle is the numbing stasis which dulls all sensations and prevents mortals and immortals alike from transcending this world. As such, the Clan is split over the role of Apophis within the Clan: Older stories tell how the poison of Apophis is what turned Set into a vampire that he contracted due to a scheme of Osiris during his protection of Re. Some theologists also point out that it was Set who originally defended Ra from the Chaos Serpent and, although rumors of Set’s conversion into a cultist of the Corruptor persist, theophidian myths tell how Set finally managed to kill Apophis after his banishment and ate its heart, gaining its powers for himself, showing the ambition of the Antediluvian to merely use the powers of Apophis to destroy his hated enemy Osiris. Other Typhonists, among them luminaries like Hesha Ruhadze, rever the serpent Apep as the master of Set, to whom they are bound through their service to the Antediluvian. 
Mummies who hear these stories believe that the vampire delude themselves out of fear that the Great Serpent will soon come to claim its due from its wayward slaves.
Werewolf: The ApcalypseEdit
Those Garou with contact to the Reborn believe that Apophis is just another name for the Wyrm. The Silent Striders use the term "Apophis", to describe the corrupted Wyrm and the term "Apep" to describe the original Wyrm of Balance, in order to differentiate the pure form from the corrupted.