These bosses are tied to quests. Though you don’t have to take the quests on to fight them, you should get them done for the quest rewards and for completion’s sake.
ESO: Blackwood All World Boss Locations
Old Deathwart
This giant monster frog, also known as Death Hopper, can be found in the Black Marshes province, located in the northeastern part of the Blackwood at Old Deathwart’s Pond.
You need to deal with this boss as a part of “A Reign of Frogs” quest that also requires you to collect singing frogs.
Old Deathwart can be found in a large pond with Kotu Gava mosquitos, which are the main source of its nutrition. During the battle it will eat the mosquitos to replenish its life, so be aware of this and try to keep him from chowing down.
Once you beat Old Deathwart, you will be rewarded with the Wart-Wacker achievement.
Bhrum and Koska
The twin minotaurs Bhrum and Koska can be found at Shardius’s Excavation in the province of Cyrodiil located in the southwestern part of Blackwood.
These two bosses are a part of the “Legend of the Man-Bull” quest, which will also ask you to recover any heirlooms or curios in the very same area.
The fight takes place with both twins simultaneously. They wield large axes and can be more easily handled with ranged abilities over melee.
Once Bhrum and Koska have fallen, you will earn the Bull-Fighter achievement.
Ghemvas the Harbinger
This four-armed Ruinach boss can be found at The Shattered Xanmeer in the south of Blackwood.
This boss is a part of the “Call of the Ruinach” quest that also requires you to sanctify the dead with the special oil.
The fight starts with a group of cultists summoning Ghemvas, who then summons three more Dremoras to assists him in battle. Focus on killing the three Dremoras first, and then work on Ghemvas himself, as the Dremoras can be incredibly dangerous.
If you beat this boss, you will be rewarded with the Havocrel Harrower achievement.
Sul-Xan Ritual Site
The Sul-Xan bosses are grouped at their ritual site, which can be found in the central area of Blackwood.
The fight includes eight enemies:
Yaxhat Deathmaker Veesha the Swamp Mystic Nukhujeema Shuvh-Mok Sul-Xan Mystic Sul-Xan Stinger Sul-Xan Conjurer Sul-Xan Bounty Hunter
But that’s not it, as they will also summon allied beasts to help them, so it’s going to be quite a brawl.
The best way to defeat all the bosses is to use circular AoE spells that will cover the entire range of enemies.
When you beat all of them, you will unlock the Sul-Xan Sacker achievement.
Xeemhok the Trophy-Taker
Xeemhok, the Argonian Behemoth, can be found in his own lair at the Xeemhok’s Lagoon located in the ruins near Vunalk at the southeast of Blackwood.
This boss is a part of “The Trophy-Taker” quest, which also requires you to collect the tokens of the dead challengers who tried to kill Xeemhok.
Fortunately you’re fighting this one all on his lonesome, so you don’t have any distractions to worry about.
Once you beat this boss, you will earn the Trophy-Taker’s Taker achievement.
Toad-Tongue Fire Mage
This goblin boss resides in the Toad-Tongue War Camp on the north of Blackwood.
Approach the camp and sit on the empty throne. This will instigate the boss to fight you. He will summon his two bog dogs, Thigz and Vigz, as well as his war chief Zathmoz.
Kill his allies first and then focus on the goblin mage. After you defeat him, take the documents, and this will successfully unlock the Saviour of Blackwood achievement.
Those were all world boss locations in Elder Scrolls Online: Blackwood. You can also find more Elder Scrolls Online guides on our dedicated hub page.
