Uber Uniques are among the hardest items to find, given their incredibly low drop chance. The chance is so low, most class builds don’t even list them as best-in-slot because it’s near impossible to find one. That’s where target farming comes into play.
Season of Blood introduced a handful of bosses that you can summon, each of which have a chance to drop specific Uber Uniques. These require specific materials; for example, summoning Duriel, King of Maggots requires two Mucus Slick Eggs and two Shards of Agony.
With those two materials in hand, you head straight for the Pestilent Altar in the Gasping Crevasse dungeon in Kehjistan and summon Duriel.
Now, getting Mucus Slick Eggs in Diablo 4 is a bit of a hike. You not only have to knock out World Tier 3, but gather other items to summon a completely different boss, the Echo of Varshan. So, start by:
Unlocking World Tier 4.
While on World Tier 3, complete the Fallen Temple capstone dungeon and you’ll unlock the next difficulty. Set your game to World Tier 4 from here on out.
Gather the Gurgling Head, Blackened Femur, Trembling Hand, and Malignant Heart.
You can either complete Tree of Whispers bounties or kill Grotesque Debtors. The former can appear in Legion events, Blood Harvests, around World Bosses, and near world events like bounties. If you come across a Debtor, kill it; otherwise, Grim Favors it is!
Summon and defeat Echo of Varshan.
Now head to the Malignant Burrow, which is located right next to the Tree of Whispers. At the end of the dungeon is the Malignant Altar, and presenting one of each body part will summon Echo of Varshan. Upon his death, he can drop Mucus Slick Eggs!
That’s all there is to know about how to get Mucus Slick Eggs in Diablo 4. The best strategy would be to collect multiple body parts, that way you can summon Echo of Varshan back to back. You do need two Mucus Slick Eggs for Duriel, after all. You can use the same strategy with the eggs to, again, fight Durial in quick succession. Good luck with your drops!