Nearly EVERY SINGLE EXAMPLE on this list is a spoiler by default due to being a Final Boss, and ALL of them will be unmarked. You have been warned!
- As he's the final boss of Adventure, Nightmare doesn't get even a mention of his existence until the finale reveals he was the reason King Dedede sealed the Fountain of Dreams, meaning talking about him spoils the entire reason behind the plot.
- The True Final Bosses of the "Dark Matter Trilogy", Dark Matter, Zero, and 02, inevitably fall under this for obvious reasons, more or less.
- However, Dark Matter in Dream Land 2 is a rare subversion for these types of villains: While the game itself keeps Dark Matter's appearance a mystery, the English manual outright states that it destroyed the Rainbow Bridges and is controlling King Dedede.
- Kirby Super Star:
- Dyna Blade's role in the game is set up as a monster destroying Dream Land's crops, but in truth she's just a mother wanting to feed her babies.
- The only non-spoiler thing about Marx and Nova is the former telling Kirby about the latter at the beginning of Milky Way Wishes.
- While, unlike most other villain examples, Drawcia's existence and Big Bad role in Kirby: Canvas Curse can be noted without spoiling anything, it's hard to seriously talk about her without mentioning the fact her Drawcia Soul form heavily influences many moves for almost every Superboss and several regular Final Bosses that appeared after her introduction.
- Galacta Knight is a spoiler in every game he appears in; he's the final boss in Kirby Super Star Ultra and Kirby: Planet Robobot's Meta Knightmare Ultra and Meta Knightmare Returns respectively, a True Arena-exclusive fight in Kirby's Return to Dream Land, a bait-and-switch part of a major lore reveal in Kirby Star Allies, and the Final Boss of Super Kirby Clash, with two new forms, to boot.
- Yin-Yarn himself isn't a spoiler as much as the two knitting needles being his true identity.
- Kirby's Return to Dream Land:
- Any serious talk about Landia will inevitably give away the fact he's actually a Hero Antagonist guarding the Master Crown from Magolor.
- Magolor is the Big Bad of Return to Dream Land.
- While there is some slight amount of spoilers relating to the Master Crown being the target for Magolor's secret villain scheme in the original game, come the Deluxe version it gains a massively boosted role in the Magolor Epilogue, recontextualizing just about everything behind Magolor's original scheme.
- Kirby: Triple Deluxe: Taranza and especially Sectonia are very pivotal to the game's climax and overall story.
- Kirby and the Rainbow Curse:
- Bringing Claycia up is impossible without getting spoiled because her boss battle reveals that she was possessed by Dark Crafter.
- Dark Crafter's mere existence is Kirby and the Rainbow Curse's big twist, especially since it reveals that Claycia was under its control the whole time.
- President Haltmann and especially Star Dream both play a huge role in the climax and plot of Kirby: Planet Robobot.
- Kirby Star Allies:
- Subverted with Hyness due to being literally the first character we see in the game's opening cutscene. His backstory and his corrupt form revealed in Heroes in Another Dimension plays this straight, though.
- Void Termina is the Walking Spoiler of all Walking Spoilers, as his spoiler-heavy relevance spans the entire Kirby franchise, past, present, and likely future.
- Morpho Knight has near-zero foreshadowing to its existence before the actual fight in Guest Star ??? Star Allies Go! It's almost impossible to talk about it without spoiling anything.
- In Forgotten Land, it also works as one of the True Final Bosses along with Chaos Elfilis, and with its presence unannounced beforehand, the only hint of its appearance in the game is a familiar orange and red butterfly being swept into the vortex alongside the rest of Popstar's inhabitants in the intro.
- Kirby and the Forgotten Land:
- The Beast Pack's leader, Leongar, and by extension the entire Beast Pack, had been manipulated by Fecto Forgo to capture the Waddle Dees against his will.
- As per the series' status quo, Fecto Forgo is also this given its status as the final boss.
- Several extra game mode bosses, such as HR-D3 and Shadow Dedede, fall under this for the same reasons, more or less.
