Molanisks are Slayer monsters that require level 39 Slayer to kill. A Slayer bell is necessary to fight them. Players should remember to bring a light source when fighting them, as they are only found underground. Despite what their level would suggest Molanisks do unusually low damage, meaning a relatively mid-level player with half-decent armour should easily be able to kill several of them.
Molanisks reside in the Dorgesh-Kaan South Dungeon inside Dorgesh-Kaan, which can be reached either by Fairy ringA•J•Q, by Dorgesh-kaan sphere, or through the Dorgeshuun mine from Lumbridge. The Dorgesh-Kaan South Dungeon itself is located directly south of the city and can be accessed by going directly south until you come to the Dorgesh-Kaan agility course. Once there, a ladder can be used into the dungeon proper where, slightly to the south-east (take the first pathway to the east, near the water) a single Molanisk can be seen.
Molanisks are found attached to cave walls and must be lured off with a Slayer bell to allow players to attack them. When lured off the wall, they are aggressive towards the player who lured them off with the bell. Molanisks respawn relatively quickly, so players who want to conserve run energy can just stay at the same respawn location. However, after the 22 June2009update for run energy and extended agility courses, players with even mid-range levels of agility can usually recover their runenergy while fighting a molanisk. For these players, it is thus faster to run between two molanisks, the best pair being those south of the fairy ring.
Molanisks have a low maximum hit and their attacks aren't very accurate, however their hits can mount up. Therefore, a small amount of food is recommended up to defence level 80 for larger tasks (over 100). An alternative would be picking up bones and using the spell Bones to Bananas or Bones to Peaches. Due to their maximum hit being so low, level 60 defence and adamant armour is sufficient.
In addition to not showing up as a yellow dot on the minimap while on the wall, they can also be seen from the floor above while doing the agility course, which further shows that they are coded as objects rather than NPCs.