Magmus is a powerful OozeBoss-like foe which can be found in the final room of Heart of the Shiverpeaks Level 3. Magmus spawns a large number of Oozes at beginning of battle. After its death, many Ooze enemies spawn which must be killed to make the reward chest spawn.
When Magmus is aggroed, many smaller oozes appear around him; when Magmus dies, even more Magma Blisters will spawn. Careful pulling is recommended so your party doesn't get overwhelmed. Note that several oozes use Ooze Division, further increasing the size of the mob.
Unlike most other boss-like foes, Magmus has natural regeneration and will heal over time.
Magmus is immune to burning and has heavy resistance against fire damage. Also, like all oozes, Magmus is not fleshy.
If you have pulled him into the tunnel (near the Beacon of Droknar), and do enough damage to kill him, he will instead become invincible and non-hostile. He will then run back to the center of the room and die.
BUG: Hard Mode: Sometimes all of the oozes continiously divide creating more than 100 oozes and do not actually lose the health they are supposed to, and instead fills the room full of over 100 lvl 26 full health oozes of various sorts thanks to the Ooze Split skill.