Bosses

Bosses are an enemies which are generally encountered at the end of a chapter or act. They have more health, do more damage and are generally more aggressive. These regularly feature a health bar on-screen while the battle is happening.

The bosses are presented in the order they show up within the games. Repeated names are when the protagonist fights the boss again either in the story or mission mode.

Classic Series

Ninja Gaiden (arcade)

1. Sumo Wrestler
2. Road Warriors
3. Claw Triplets
4. 2 Sumo Wrestlers
5. Road Warriors
6. Bladedamus

Ninja Gaiden (NES)

1. The Barbarian
2. Bomberhead
3. Basaquer
4. Kelbeross
5. Bloody Malth
6. Masked Devil
7. Jaquio
8. The Demon

Ninja Gaiden II: The Dark Sword of Chaos

1. Dando
2. Baron Spider
3. Funky Dynamite
4. Naga Sotuva
5. Ashtar
6. Kelbeross
7. Jaquio
8. Possessed Jaquio

Ninja Gaiden III: The Ancient Ship of Doom

1. Mantis Warrior
2. Night Diver
3. Great Kogane
4. Sandeater
5. BIO-NOID Doppelgänger
6. H. P. Clancy

Ninja Gaiden (Game Gear)

1. Monk of the Red Tiger Cult
2. Totenkopf
3. Mr. Tsin
4. Head of the Red Tiger Cult
5. Demon Totem
6. Shiragane

Ninja Gaiden Shadow

1. Cyborg Spider
2. Gregory & Jack
3. Colonel Allen
4. Nobleman Fuukisai
5. Emperor Garuda

Ninja Gaiden (Master System)

1. Sumo Wrestler
2. Yakuza Oyabun
3. Tsutenkaku Samurai
4. Jetpack Soldier
5. Ice Ninja
6. Stone Golem
7. Kabukimono
8. Shogun of Darkness

Ninja Gaiden X

1. Jô Hayabusa

Ninja Gaiden: Ragebound

1. Ryu Hayabusa
2. Gurthka
3. Rhyvashi
4. Demon Eels
5. Obsidrae
6. Deikrag
7. Rhyvashi
8. Ship Defense System
9. Bio Flamethrower
10. Bio Titan
11. Bio Amalgam
12. Jagäzk

Endless Struggle

1. Gurthka
2. Obsidrae
3. Rhyvashi
4. Deikrag

Modern Series

Ninja Gaiden 2004/Black/Sigma/Sigma+

1. Murai
2. Masakado
3. Doku (Sigma Only)
4. Dynamo
5. Hydracubus
6. Bone Dragon
7. Gamov (Sigma Only)
8. Hydracubus
9. Alma
10. Alternator (Sigma Only)
11. 2 Vigoor Military Tanks
12. Vigoor Military Helicopter
13. Electric Worm
14. 2 Electric Worms
15. Paz Zuu
16. Doku
17. Nicchae & Ishtaros (Sigma Only)
18. Yotunfrau
19. Fire Worm
20. 2 Fire Worms (Sigma Only)
21. Smaugan
22. Awakened Alma
23. Spirit Doku
24. Nicchae (Optional)
25. Ishtaros (Optional)
26. Marbus
27. Vigoor Emperor
28. Devil Incarnate Murai

Ninja Gaiden II/Sigma 2/Sigma 2+

1. Buddha Statue (Sigma Only)
2. Rasetsu
3. Buddha Statue (Sigma Only)
4. Genshin
5. GigaDeath
6. Godomus
7. Alexei
8. Statue of Liberty (Sigma Only)
9. Tengu Brothers (Sigma Only)
10. Water Dragon
11. Giant Skeleton Wolf
12. Volf
13. Marbus (Sigma Only)
14. Genshin
15. Nuclear Armadillo
16. Godomus
17. Zedonius
18. Obaba (Sigma Only)
19. Giant Death Worm (NGII Only)
20. 2 Quetzalcoatl (NGII Only)
21. Black Dragon (Sigma Only)
22. Quetzalcoatl
23. Elizébet
24. Tengu Brothers (Sigma Only)
25. Genshin
26. 2 Nuclear Armadillos (NGII Only)
27. Marbus (Sigma Only)
28. Zedonius
29. Volf
30. Tengu Brothers (Sigma Only)
31. Alexei
32. Fiend Genshin
33. Elizébet
34. Dagra Dai
35. Vazdah

Ninja Gaiden: Dragon Sword

1. Red Dragon (Optional)
2. Red Dragon
3. Yotunfrau
4. Paz Zuu
5. Giant Brute
6. Spirit Doku
7. Smaugan
8. Ice Dragon
9. Obaba
10. Rasetsu
11. Ishtaros
12. Vigoor Emperor
13. Nicchae
14. Dark Dragon

Ninja Gaiden 3/Razor's Edge

Story Bosses

1. Steel Spider
2. Regent of the Mask
3. 3 Alchemists
4. IDE-1011 Manta
5. 3 Sword Alchemists (Razor's Edge Only)
6. Giganotosaurus
7. Regent of the Mask
8. Lovelace
9. Obaba
10. Epigonos
11. 3 Goddess Prototypes (Razor's Edge Only)
12. 2 Steel Spiders
13. Ashtear Higgins
14. Regent of the Mask
15. Cliff Higgins
16. Theodore Higgins
17. The Goddess

Tests of Valor Bosses (Razor's Edge Only)

1. Doku
2. Volf
3. Zedonius
4. Alma
5. Genshin
6. Marbus
7. Genshin
8. Elizébet
9. Alexei
10. Fiend Genshin

Yaiba: Ninja Gaiden Z

1. Holy Roaster
2. Robotic Defense Unit
3. The Terrible Two
4. Ryu Hayabusa
5. Alarico del Gonzo