Below are the monsters found in Ys IX: Monstrum Nox for the Monster Zoologist trophy!
Balduq Prison – Depths
- Ratoo
- Nooze
- Plutoad
- Graem-Gil
- Graem-Ganeaux (Chapter 6)
Tranquil Underpass
- Moorgarth
- Anxigas
Cloaca Maxima
- Anxigas
- Plutoad
- Cuhanni
Dry Moat Ruins
- Vazuli
- Zafange
- Dunpede
- Roche
- Hornville
Estatte Road
- Channam
- Ratni
- Lubregia
Concealed Path
- Culeiyo
- Mudhu
- Mushahr
- Tarantiel
- Tarantiel Egg
- Veidon
Mount El Dore
- Mushahr
- Jaganni
- Mundura
- Hornville
Blocked Path
- Plutoad
- Roche
- Cuhanni
- Tarantiel
Decrepit Underpass
- Moorgarth
- Gloggury
Groaning Grotto
- Formi
- Formian
- Disgaze
- Adamangelo
Milianne Plains
- Gublin
- Rob-Gublin
- Vrogium
Emain Macha
- Gaspard
- Zol-Gublin
- Hyueille
Keening Highlands
- Ras-Gublin
- Jyacomo
- Vaume
- Ratrilarda
Quarry Ruins
- Gaulgium
- Diglem
- Piouvre
- Dig-Merta
- Droll
Ciel Canyon Road
- Cel-Ratni
- Nipantu
Woodlands of Woe
- Gloggury
- Wogene
Road to Hidden Treasure
- Mudhu
- Disgaze
Alchemy Wing
- Divarse
- Voldon
- Valvalchia
- Niktravha
- Avaluga
- Adichivo
Ancient Battlefield
- Ras-Gublin
- Reyzard
- Yammer
- Mudo-Veidon
- Diglem
Balduq Fortress of Yore
- Chilvalier
- Melai-Siga
- Vrovollo
- Freizie
- Dymitri
- Lamdian
- Despusa
- Depth Gigan
Lemures (Ch. 1)
- Tarylux
- Garguleo
- Sherpent
- Gevaudan
Lemures (Ch. 2)
- Odh
- Garguleo
- Logier
- Tarylux
- Snerpent
- Grosporte
Lemures (Ch. 3)
- Odh
- Garguleo
- Snerpent
- Logier
- Pyrion
- Tarylux
- Gevaudan
- Kosmarion
- Tudhor
- Grosporte
- Kahazh
Lemures (Ch. 4)
- Odh
- Garguleo
- Snerpent
- Kosmarion
- Logier
- Tudhor
- Anjy
- Grautney
- Logillon
- Gevaudan
- Zeraphan
- Pyrion
- Luciluphan
- Grosporte
- Disastro
Lemures (Ch. 5)
- Zes-Pyrion
- Odh-Mea
- Gi-Anjy
- Valdoriga
- Grautney
- Rabby
- Logillon
- Kahazh
- Zeraphan
- Grosporte
- Neflude
- Malvillion
- Pieretta
- Luciluphan
- Varlukan
Lemures (Ch. 6)
- Zes-Pyrion
- Odh-Mea
- Gi-Anjy
- Valdoriga
- Logillon
- Kahazh
- Rabby
- Grautney
- Grosporte
- Malvillion
- Pieretta
- El-Tarylux
- Luciluphan
- Zerasporte
- Curimanthe
- Zea-Grautney
- Neflude
- Valron
- Vakhmedhu
Lemures (Ch. 7)
- Valron
- El-Tarylux
- Lu-Anjy
- Rabby
- Fol-Odh
- Malvillion
- Aspiyus
- Neflude
- Varlukan
- Logillon
- Zea-Grautney
- Luciluphan
- Melgevaudan
- Baturolle
- Zerasporte
Lemures (Ch. 8)
- Valron
- Lu-Anjy
- Fol-Odh
- Geo-Tarylux
- Aspiyus
- Varlukan
- Dei-Rabby
- Garguleo-Roa
- Melgevaudan
- Zea-Grautney
- Exceflude
- Zerasporte
- Disastyrfe
- Dio-Manthe
Lemures (Final Ch.)
- Valron
- Fol-Odh
- Lu-Anjy
- Geo-Tarylux
- Dei-Rabby
- Aspiyus
- Varlukan
- Garguleo-Roa
- Melgevaudan
- Exceflude
- Dio-Manthe
- Baturolle
- Disastyrfe
- Vakhmedhu
- Guarmedhu
Bosses
- Maretudo – Balduq Prison – Depths
- Geelzebub – Tranquil Underpass
- Glemandy – Cloaca Maxima
- Dragia Haman – Cloaca Maxima
- Rene-Vagullion – Dry Moat Ruins
- Malefious – Dry Moat Ruins
- Mes Bellator
- Regirania
- Sectocanom
- Avalodragil
- Condemned Norns
- Rene-Nygtilger
- E-Mes Bellator
- Ostroflambe
- Master Chatelard
- Chimeral Bourdon
- Chimeral Roussillon
- Chimeral Chard III
- Atra Nox Philius
- Anima Ergastulum
- Egg of Draupnir
- Vakh Medios
Wanted Monsters
- Maretudo
- Tarantiel Egg
- Tarantiel
- Dragia Haman
- Droll
- Bualadh-Orgh
Extra
- Guardsman – Balduq Prison
- Hieroglyph Knight – Chapter 4 story
- Enamudien
- Berserker Hawk
- Hieroglyph Knight Gilbert
- Disastro
- Bualadh-Orgh