Where can it be found

An area that you teleport to when you wear the 10th squad sigil

Tactic

Turn on protect mage and step away from it. Proceed to either mage it with any high level fire spell or range it with range and a cannon. Bring plenty of runes and prayer potions, along with an emergency teleport out.

Examine Message

A Greater Jungle Demon. A magical aura emanates from its hide.

Notes

Gnome warriors will aid you in killing the demon as part of the Monkey Madness quest.