Bosses in order of which I found them...

Margit the Fell Omen - Beastman of Farum Azula - Lionine Misbegotten - Godrick the Grafted - Nights Cavalry - Death Bird - Patches - Frenzied Duelist - Scaly Misbegotten - Runebear - Erdtree Avatar - Ancient Hero of Zamor - Demi-Human Chiefs - Glintstone Dragon Smarag - Redwolf of Radagon - Rennala Queen of the Full Moon - Deathbird - Erdtree Burial Watchdog - Magma Wyrm Makar - Godefroy the Grafted - Godskin Apostle - Cemetery Shade - Night's Cavalry - Deathbird - Magma Wyrm - Cemetery Shade - Onyx Lord - Commander O'Neil - Bloodhound Knight in Darriwil - Crucible Knight - Tree Sentinel - Royal Knight Loretta - Margit the Fell Omen - Omen killer - Godskin Noble - Draconic Tree Sentinel - Godfrey, The First Elden Lord - Morgott The Omen King - Starscourge Radahn - Putrid Tree Spirit - Borealis the Freezing Fog - Rykard the Blasphemer - Black Blade Kindred - Nights Cavalry - Stone Digger Troll - Flying Dragon Agheel - Mad Pumpkin Head - Grave Warden Duelist - Night's Cavalry - Guardian Golem - Black Knife Assassin - Ulcerated Tree Spirit - Erdtree Burial Watchdog - Miranda Blossom - Tibia Mariner - Royal Revenant - Fire Giant - Godskin Duo - Dragonkin Soldier - Kindred Rot - Commander Niall - Dragonkin Soldier of Nokstella - Astel, Naturalborn of the Void - Glintstone Dragon Adula - Alecto, Black Knife Ringleader - Loretta, Knight of the Haligtree - Cemetry Shade - Cleanrot Knight - Crystalians - Crystalian - Demi-Human Queen Margot - Red Wolf of the Champion - Ancient Dragon Lansseax - Black Knife Assassin - Ancient Hero of Zamor - Omenkiller and Miranda the Blighted Bloom - Grave Warden Duelist - Putrid Grave Warden Duelist - Great Wyrm Theodorix - Misbegotten Crusader - Mohg the Omen - Crucible Knight Siluria - Fia's - Erdtree Burial Watchdog Duo - Falling Star Beast - Battlemage Hugues - Nox Duo - Elder Dragon Greyoll - Beast of Farum Azula - Decaying Ekzykes - Flying Dragon Greyll - Crucible Knight & Misbegotten Warrior - Spirit Caller Snail - Black Knife Assassin - Perfumer Tricia & Misbegotten Warrior - Fire Prelate - Abductor Virgins x2 - Crystalian Spear & Crystalian Ringblade - Wormface - Sanguine Noble - Elemer of the Briar - Crucible Knight & Crucible Knight Ordovis - Demi-Human Queen Gilika -Fell Twin x 2 - Ancient Hero of Zamor - Astel, Stars of Darkness - Death Rite Birdx2 - Tibia Mariner - Spiritcaller Snail - Malenia Blade of Miquella - Dragonlord Placidusax - Sir Gideon Ofnir, the All-Knowing -
Hoarah Loux, Warrior - Radagon of the Golden Order -
Elden Beast