Unique

• 

  The Skull Ghost from EBF1 and EBF3

• 

  The Spirit from EBF2 and EBF4

• 

  The Eyeball from all games bar EBF2

• 

  The Rune/Razor Claw from EBF3 and EBF4

With the exception of nearly all bosses, throughout the Epic Battle Fantasy series, there have only been a few non-boss foes that seem to defy categorization, due to their unique aesthetics and abilities. This also includes foes that were formerly unique until they were introduced respective families. There are also a few mini bosses/elite foes that have spawned families. Some foe groups that have only two or three members can also be considered unique.

Throughout the main series, there have only been four non-boss foes that remain ungrouped, despite having possible relationships.

Unique Species

Epic Battle Fantasy

As this is the first game, the majority of foes can be considered unique and ungrouped. Only the Furry Slime and King Slime were related as a supergroup (Slimes and Big Slimes).

• Eyeball - Remains ungrouped throughout the whole series, despite being heavily associated with the Beholder and the Eyes group.
• Beholder - May have inspired The Devourer in EBF5.
• Haunted Tree - Remained unique in EBF3, but spawned the Evil Plants family in EBF4.
• Defender - Knocked down to elite foe status in EBF4. Remained ungrouped until EBF5, where it inspired the Defenders group.
• Spiral Crab - Renamed Beach Crab in EBF3 and also spawned the Crabs family.
• Ancient Eye - Became the first member of the Eyes family in EBF3.
• Skull Ghost - Consistently unique, but may be considered a proto-Wraith.

Epic Battle Fantasy 2

There are three (technically six, if you include two bosses and a helper) new unique foes that were introduced in EBF2.

• Sand Worm and Sand Tail - They, alongside with the Evil Worm and Evil Tail of EBF3, would spawn the Worms (Greater) family in the same game.
• Spirit - Remains unique in aesthetics, abilities, and gimmick (being foes that start off with Auto-Revive, like PHOENIXES). May also be considered a proto-Wraith due to its abilities despite the lack of resemblance. Similar foes can be found in Bullet Heaven 2.
• Zombie Hydra - (Mini)bosses that (alongside the Pyrohydra) spawned the Hydras and Dragons supergroup from EBF3 onwards.
• Drill Bot - Unique from EBF2 to EBF4. Inspired the Flybot group in EBF5, despite not appearing in that game.
• Giga Golem - Spawns the Golems family from EBF3 onwards, barring a few precursors.

Epic Battle Fantasy 3

One unique foe were introduced in EBF3, while the other three were bosses that inspired later foes.

• Giant Squid - Inspired the Squid family in EBF4 and EBF5.
• Tundra Mammoth - Knocked down to elite foe status in EBF5 and became the first of the Mammoths.
• Rune/Razor Claw - Recurring helpers (like the Runes) of Akron and the Praetorian MKII that are unique in aesthetics and abilities. May be considered a relative to the Runes, despite having more complex abilities like Flybots and Eyes.
• Pyrohydra - Boss that inspired the Dragons and Hydras supergroup (see Zombie Hydra above).

Epic Battle Fantasy 4

No new unique foes were introduced in this game.

Epic Battle Fantasy 5

• Snowflake - May be considered a proto-Arcade foe for sharing many aesthetic similarities, like the Pixels.
• The Devourer (and other parts) - May have been inspired by the Beholder, with separate appendage-like entities like the Giant Squid.