In the ESO Monster Trophy Guide all the items are listed up with the locations where you can get them. These here are just the best locations to farm them, there are more possible spawn locations. You need those Monster Trophies for the Atronach Element Collector, Chitin Accumulator, Dwarven Secrets Gatherer, Monstrous Component Collector, Nature Collector, Tamriel Beast Collector, Undead Hoarder and the Oblivion Shard Gatherer Achievement. Thanks to @Zayoo from PC EU for providing the list!

Table of Contents:

Atronach Element Collector

Here you can find the list with all the items needed for the Atronach Element Collector. Once you have collected all the pieces, you will be awarded with the “Elemental White Dye”.

Trophies
Smoldering Ember Heart Flame Atronach
Craglorn –> Spellscar
Fleshy Symbiont Flesh Atronach
Malabal Tor –> Around Abamath
Everfrost Frost Atronach
Craglorn –> Spellscar
Crackling Lodestone Storm Atronach
Craglorn –> Spellscar

Chitin Accumulator

Here you can find the list with all the items needed for the Chitin Accumulator. Once you have collected all the pieces, you will be awarded with the “Mudcrab Maroon Dye”.

Trophies
Petrified Spider Egg Spider
Glenumbra –> Spindleclutch I (Dungeon)
Calcified Cuttle Kwama
Shadowfen –> Onkobra Kwama Mine (Delve)
Razor-Edged Mandible Shalk
Stonefalls –> Sulfur Pools
Luminous Blood Sac Hoarvor
Grahtwood –> Area East of Haven
Shadowfen –> Xal Ithix (Farm SW))
Polished Shell Shard Mudcrab
Wrothgar –> All Beach Areas
Prized Barb Scorpion
Craglorn –> Scorpion Ravine
Mulifaceted Eye Nix Hound Stonefalls –> Around Geymist Falls (NW on map)
Gossamer Winglet Wasp Deshaan: Silent Mire

Dwarven Secrets Gatherer

Here you can find the list with all the items needed for the Dwarven Secrets Gatherer. Once you have collected all the pieces, you will be awarded with the “Faded Dwemer Scholar Red Dye”.

Trophies
Perfectly Balanced Gyro Dwarven Sphere
Bangkorai –> Razak’s Wheel (Delve)
Whirring Dynamo Dwarven Spider
Bangkorai –> Razak’s Wheel (Delve)

Monstrous Component Collector

Here you can find the list with all the items needed for the Monstrous Component Collector. Once you have collected all the pieces, you will be awarded with the “Trolls Fur Brown Dye”.

Trophies
Werewolf’s Cameo Werewolf
Glenumbra –> Aldcroft Swamp (South and Southwest of Wolf’s Camp)
Nose Shackle Ogrim
Coldharbour –> Mine Outside Tower of Lies
Troll Skull Troll Eastmarch: Around Thuvald’s Logging Camp
Ogre Toe Ring Ogre
Greenshade –> Carac Dena (Delve)
Reaper’s March –> Little Ozur’s Camp
Stormhaven –> Bonesnap Ruins
Stony Heart Gargoyle
Bangkorai –> Qharroa Ruins
Alik’r Desert –> Lost City of the Na-Totambu (Publ Dungeon)
Second Skin Lamia, Lamia Curare
Coldharbour –> South of the Moonless Walk
Shadowfen –> Arx Corinium (Group Dungeon)
Flawless Tail Feather Harpy
Bangkorai –> Blackheart Haven (Dungeon)
Wrothgar –> Colperch Cavern (Delve)

Nature Collector

Here you can find the list with all the items needed for the Nature Collector. Once you have collected all the pieces, you will be awarded with the “Spriggan Green Dye”.

Trophies
Primal Sproutling Spriggan
Grahtwood –> Vinedeath Cave (Delve)
Greenshade –> Rootwater Grove
Lashing Tentacle Strangler
Malabal Tor –> Blackvine Ruins (Delve)
Brass Anklet Nereid
Greenshade –> Nereid Temple Cave (Near Dread Vullain)
Imp’s Effigy Imp
Glenumbra –> Area North of Daggerfall
Icebound Vertebrae Ice Wraith Eastmarch –> Hall of the Dead (Public Dungeon)
The Rift –> Snapleg Cave (Delve)
Knotted Heart Lurcher
Bangkorai –> Jackdaw Cove
Greenshade –> Rootwater Grove
Glowing Remnant Wisp
Stonefalls –> Crow’s Wood (Public Dungeon)
Shadowfen –> Deep Graves (South and a little East on the map)
Eastmarch –> The Chill Hollow (Delve)
The Rift –> Snapleg Cave (Delver)

Tamriel Beast Collector

Here you can find the list with all the items needed for the Tamriel Beast Collector. Once you have collected all the pieces, you will be awarded with the “Beast Collector Violet Dye”.

Trophies
Shimmering Alit Bezoar Alit
Grahtwood –> The Gray Mire
Kenarthis Roost –> Beach Area West of Eagles Strand
Magnificent Bat Pelt Giant Bat
Stonefalls –> Crows Wood (Public Dungeon)
Grahtwood –> Cave of Broken Sails
Gnarled Bear Claw Bear / Black Bear
Auridon –> Shattered Grove
Wolf’s Tooth Necklace Wolf
Auridon –> Shattered Grove
Cat’s Claw Sabre Cat, Senche Tiger The Rift –> Areas around and North of Trevas Farm
Inert Egg Lamia, Lamia Curare
Reaper’s March –> Thormar
Malformed Kagouti Tusk Kagouti
Shadowfen large area around Gandranen Ruins (Delve)
VVardenfell –> East of Falensarano Ruins
Huge Mammoth’s Tooth Mammoth
Eastmarch –> Area South of Thief Mundus
Malabal Tor –> Vulkwasten & Treehenge
Buzzing Spine Wamasu
Grahtwood –> The Gray Mire (Southwest)
Shadowfen –> Most of the Swamp Area
Bile Gilt Bull Netch
Vvardenfell –> Nchuleftingth
Bal Foyen –> All over the map
Cruel Collar Jackal
Alik’r Desert –> Ogre’s Bluff
Alik’r Desert –> Between Lekis Blade and Lost City of the Na-Totambu
Hew’s Bane –> No Shira Citadel (NE Part)
Craglorn –> Area west of Belkarth
Scaly Durzog Hide Durzog
Wrothgar –> Nikolvarra’s Kennel (Delve)
Auridon –> Tootmaul Gully (Public Dungeon)
Stormhaven –> Bonesnap Ruins (Public Dungeon)

Undead Hoarder

Here you can find the list with all the items needed for the Undead Hoarder. Once you have collected all the pieces, you will be awarded with the “Gangrene Green Dye”.

Trophies
Hand of Glory Scaled Court Zombie
Craglorn –> Skyreach Catacombs
Chattering Skull Skeletal Fire Mage / Assassin
Craglorn –> Skyreach Catacombs
Wraith Shackle Wraith
Rivenspire –> Crypt Of Hearts I (Dungeon)
Deshaan –> Forgotten Crypts (Public Dungeon)
Twitching Draugr Hand Draugrs
Eastmarch –> Direfrost Keep (Dungeon)
Eastmarch –> Hall of the Dead (Public Dungeon)
Ectoplasmic Discharge Spectrals, Ghosts
Auridon –> Tanzelwil
Malabal Tor –> Shael Ruins (Delve)
Crypt Jar Mummy Alik’r Desert –> The Lost City of the Na-Totambu (Public Dungeon)
Alik’r Desert –> Tu’whacca’s Throne (North of Goat’s Head Oasis Wayshrine)
Shadowfen –> Gandranen Ruins (Delve)

Oblivion Shard Gatherer

Here you can find the list with all the items needed for the Oblivion Shard Gatherer.

Trophies
Banekin Horn Banekin Bangkorai –> Damars Farmstead (Northwest of Old Tower Wayshrine)
Auridion –> Mehrunes Spite Delve (NW on the map)
Shadowfen –> Broken Tusk Delve (NE on the map)
Daedric Dewclaw Clannfear Coldharbour –> Black Forge
Grahtwood –> Around Laeloria
Imperial City Sewers –> Sewers
Burning Daedroth Eye Daedroth
Bangkorai –> Damars Farmstead (NW of Old Tower Wayshrine)
Blighted Iron Collar Scamp
Stormhaven –> Vanne Farm
Imperial City Sewers –> Sewers
Spider’s Crown Spier Daedra Coldharbour –> Around the lake in the south east
Shadowfen –> Broken Tusk Delve (NE on the map)
Spider Daedra Bosses (For example Spindleclutch 1)