Mother Mallum - Mahey'ish Medron in the ancient, all but forgotten, Saradominist language - is the queen of the Sea Slugs and resembles an enormous mollusk, and she plans to take over RuneScape. She currently has control of the Fishing Platform and Witchaven. She first reveals herself to the world during The Slug Menace quest when the player is unknowingly tricked into releasing her. She attempted to conquer RuneScape over 4000 years ago but was stopped by the Temple Knights. She communicates using a human body as a host, and during the last part of the Slug Menace quest, she tries to obtain the player character as a new host. The player is ultimately saved from her by being teleported out of the cave by Savant.
How Mother Mallum came to be is unknown, and the earliest records of her are the Temple Knights' HQ, which cannot have been written earlier than the middle-to-late Third Age. However, the Slug Queen is known to be much, much older than that, due to the fact that she invaded realms before Gielinor.
She had attempted to achieve global domination on Gielinor in the late Fourth or early Fifth Age, having accomplished this in other worlds, by possessing various important political figures, but this plot was narrowly stopped by the Temple Knights. She was imprisoned, but escaped in the Fifth Age, when she was permanently defeated, ending the Sea Slug Conflicts.
Temple Knight Crusade
At an unspecified date in Gielinorian history, described as "centuries ago", Mother Mallum emerged from the sea with an army of slugs. Mallum, who had set her plans to possess the important political figures of the world and thus rule it in motion, was fought by both a secretive military organisation known as the Temple Knights as well as the White Knights, a closely linked organisation who served the Temple Knights.  The White Knights suffered massive losses, losing many men to Mother Mallum's mind control, whom she took with her to her base of operation: a large submarine fortress known as the Slug Citadel, located off the coast of what is now Kandarin (more precisely, east of Ardougne).
The few knights that had escaped the slugs proceeded to devise a method to remove the possession, which succeeded albeit with great effort, before forming a plan to stop her - the Temple Knights launched a crusade to the Slug Citadel although they soon realised they would not be able to kill her, They fought the slugs and lured Mother Mallum into a cave. There, she was trapped and the knights magically sealed the cave with a door using modified runestones.  Mother Mallum was imprisoned and her slugs fled to the depths of the sea, while the Temple Knights marked their victory by building statues of their men which they placed near the door. Additionally, they wrote the name of the prisoner, "Mahey'ish Medron", on the door in glyphs.
Taking over Witchaven
|“||Yes, that's it, fight, fight with all your heart. It's always so much sweeter when they resist us. Come with us. Come and be with us for all eternity.||”|
Mother Mallum's second attempt at conquest would not commence until later, in 169 of the Fifth Age. That year, the Kandarian government authorised the construction of a Fishing Platform off the coast of the small and quiet fishermen's village of Witchaven. [ ] The rich catch from the platform brought poverty to Witchaven, which had lost its only source of income. However, the fishermen soon began catching increasing amounts of sea slugs. These naturally possessed the fishermen, who, as a result, began hauling in only more slugs, while throwing all the caught fish back into the sea. Eventually, nearly all the workers of the platform, aside from the timid keeper of the platform named Bailey, who discovered he could keep the hostile fishermen at bay using fire. Witchaven's mayor, Eustace Hobb, also fell victim to the slugs' mind control.
When the villager Kent and his son Kennith went to the platform, the sea slug invasion was first discovered. They found themselves unable to leave the platform, but were rescued by the player who was sent by Kent's wife Caroline. Afterwards, the sea slugs quickly spread, taking over most of the villagers, aside from the families of Caroline, the sailor Holgart, and the fishmonger Ezekial Lovecraft. Meanwhile, a retired but still semi-active Temple Knight colonel called Jake O'Niall noticed the increasingly strange occurrences and contacted the headquarters in Falador when he noticed the mayor, who "was about as religious as a dead dog on a termite mound", had suddenly decided to renovate the shrine to Saradomin just west of the village, bringing lots of Mining equipment and, much more suspiciously, high amounts of rune essence in. The Knights' head of recruitment, Sir Tiffy Cashien, dispatched an initiate knight (i.e. the player during the Sea Slug quest), who had rescued Kennith earlier, to Witchaven to investigate the situation. By this time, the slugs had possessed large groups of enormous lobsters, who turned very aggressive as a result. The green monsters proceeded to guard the path to Mother Mallum's prison. They reported to O'Niall and had Savant, the senior mystical researcher, scan the mayor, detecting two life forms (him and his slug), although she initially thought it was an error of the analysis. They then investigated the Witchaven Shrine and found the Temple Knight prison, not knowing what it was. They had it investigated and found out about the crusade and that Mother Mallum was inside. Soon after, the mayor placed a slug on Brother Maledict's neck and commenced a plot to release Mother Mallum. The possessed priest tricked the initiate into repairing the Holy Book of Saradomin, which supposedly stated how to re-inforce the sealing enchantment. While gathering the book's lost pages, they also discovered that O'Niall had been possessed as well. The initiate repaired the book and performed the ritual, but was shocked when it actually opened the prison.
Mayor Hobb, now transformed into an aquatic creature, emerged from it and summoned the Slug Prince to kill the initiate, but the prince was slain. An enraged Hobb was then dismissed by Mother Mallum herself, who cast a teleblock to prevent Savant from rescuing the initiate. She attempted to discard Lucy and use the terrified initiate as her new host. As she was about to attack them, Savant managed to teleport the panicking initiate to safety. They reported to Sir Tiffy, who promoted them to proselyte and ordered the assassination of O'Niall.
Mother Mallum is described by the Temple Knights, whom she has fought, as a great evil due to her and her slugs' ability to attach themselves to someone's neck and take over their mind, effectively turning their victims into mindless servants that do her bidding. The victim's skin also turns to a sickly yellow colour, and longer possession results in certain "aquatic" features, such as gills and fins, developing. If freed from possession, the victims are unable to recount what had happened, and their mind is left in its state prior to the possession.
She is unable to communicate with non-slugs without a host. Unlike her spawn, she is large and powerful enough to carry her host, suspended by tendrils protruding from her mouth, rather than vice versa. Her last host was originally a small girl named Lucy, but her body aged over many decades, though her mind remained the same due to her possession. Mother Mallum is cruel and confident, deeming her plans impossible to fail, and sometimes refers to herself in plural, a trait shared by other slugs and victims. Aside from the mind possession, Mother Mallum is capable of telepathy and telekinesis, and perhaps other types of Magic as well, for she is known to be able to cast teleportation blocks.
- The name "Mallum", translated from Latin, means "evil (thing)/disaster" (although the Latin word is spelled with one L), thus making her, quite appropriately, the mother of evil.
- In the FunOrb game Armies of Gielinor, set during the God Wars, one of Zamorak's monsters is a sea slug, although it resembles Mother Mallum more than it resembles the common sea slug.
- ↑ 1.0 1.1 Jagex. Postbag 40 - "Previously, in Dorgesh-Kaan.", letter #3. RuneScape Postbags from the Hedge.
- ↑ Savant, "The Slug Menace", Old School RuneScape. "Well, this isn't the first time the Temple Knights have encountered the Mother Mallum. Centuries ago we discovered that a great evil had taken control of some of the most influential people in the world. That great evil was the Mother Mallum."
- ↑ Savant, "The Slug Menace", Old School RuneScape. "It took the few remaining uncorrupted knights all their wit and strength to devise a method of removing sea slug possession. Once freed, the Temple Knights pursued a great crusade to destroy the Mother Mallum. Unfortunately she was too powerful and the best they could do was to trap her inside a mystical prison."
- ↑ Bailey, "Sea Slug", Old School RuneScape. "It all began a few weeks ago. We pulled up a haul of deep sea flatfish. Mixed in with them we found those slug things, but thought nothing of it. Not long after that my friends began to change. Now they spend all day pulling in hauls of fish, only to throw back the fish and keep those nasty sea slugs."