List of All Overworld Bosses

Thanks to TerminatorTJM, Flash, and Harry for getting this information.
Name 	Location 	Level	Looks Like 	Picture	Drops
Al'Ville 	Crystal Caverns 	 	Human in robe with 2 dwarf mercenaries 	 	Archaeologist's, Heroic Tulors
Ali Khan 	Ascetos Desert 	1137 	Humanoid with NB Sash, paired with Snakes 	 	Snake Pit, Heroic Snake Pit
Bloody Mary 	Wild Beyond 	197 	Banshee in pack of furies 	 	Tulor's, Heroic Daemon Home, Heroic Tulor's
Bloodmauler 	Bloodwood 	111 	Solo hell hound (Red in color) 	 	Festering Hate Pool, Naktos
Cael the Destroyer 	Ascetos Deep Dessert	 	
GIANT. Head doesn't fit on screen. 	 	
Heroic Snake Pit, Cael's Hide
Desert Madman 	The Barrens 	 	Wears a ViH / Jesters Hat 	 	Imp King, Heroic Foundry, Heroic Imp Haven, Diary of a Madman
Emissary of Light 	Avalon Grasslands 	2371 	High Priestess in a Mask with Paladins and WoL's 	 	Holy Caves, Heroic Barracks, Heroic Foundry, Vial of Condensed Light, YMMB Shirt, Enid's Baldric?
Emissary of Night 	Avalon Dunes 	1480 	Mist mage with reapers and DK's 	 	Underground, Vial of Condensed Night
Gaelan Frostbeard 	The Downs 	 	Dwarf in pack of dwarves 	 	Blacksmith, Heroic Foundry, Dwarf Expedition Log
Grafvitnir 	Fafnir's Swamp 	1805 	Dark blue dragon with 2 other dragons 	 	Dragon's, Graf's Eye, Faf's Eye?
The Harvester 	Killing Fields 	 	Lich with invisible "harvested souls" 	 	Fuloran's, Heroic Fuloran
Krisatara 	Crystal Caverns 	 	Female with 2 dwarf mercenaries 	 	Archaeologists's, Heroic Forgotten
Maremita 	Crystal Caverns 	 	Human with two
dwarf bodyguards  	 	
Archeologists's, Heroic Snake Pit  
Master of the Hunt 	Avalon Plains 	756 	Wears a wolf helmet grouped with two huntresses 	 	Warriors, Heroic Imp Haven
Master of the Maze 	The Maze 	1600 	Harlequin. Usually wearing TMMB & NightSoul Helm 	 	Fuloran's, Heroic Undead Stronghold, Heroic Forgotton Dungeon, Yellow Maze Master Baldric (YMMB)
Mayline Heartflutter	Devon Forest 	285 	White seraph in a pack of seraphim 	 	Holy, Enid's, Heroic Barracks
Ogre Patriarch 	Emerald Forest 	 	Ogre chief in pack of ogres 	 	Enid's, Heroic Imp Haven
Pancho 	Dark Forest 	341 	Wears dark hood, grouped with 2-3 bandits 	 	Festering Hate Pool, Thief's
The Rat King 	Wexfordshire Valley 	73 	Human with no shirt and viking helmet 	 	Rat Charmer
Reanimated Tulor 	Winter Wold 	1425 	Solo devil 	 	Heroic Tulor, Tulor's, Festering Hate Pool
Snaggletooth 	Ratling Run 	15 	Larger Cave Ratling 	 	
Spirit of Kal'Dar 	Leinster/Kurz Road 	 	Invisible troll caster with invisible troll entourage 	 	Heroic Undead Stronghold
Stormbringer 	Ocean View 	 	Water elemental, full size with a group of ocean elementals	​​​​​ 	Heroic Daemon Home, Heroic Foundry, Ezelberoth, Blacksmith
Thunderhoof 	Drear Valley 	922 	Tall minotaur in pack of minotaurs 	 	Heroic Forgotten Dungeon
The Wanderer 	Wandering Woods 	 	Hooded human NPC 	 	Ezelberoth, Heroic Daemon, Heroic Snake Pit, Wanderer's Compass
Wargoyle 	Avalon River 	 	Big Gargoyle 	 	Underground
Xavtumal 	Crystal Caverns 	1370 	Caster with 2 dwarf mercenaries 	 	Heroic Foundry, Archaeologist's
Zender 	Zender's Wood 	497 	Caster in green robe and black baldric 	 	Heroic Barrack's Bounty, Guardian's, Zender's Diary