History UniqueEnemy / SuperMarioBros

** Only two Spikes appear in the game, both in the first room of 5-1.

** The Apprentice is a variant of the Spookum enemies found in Booster Tower (same color, different stats and spells), and only shows up in a secret path of Booster Pass. It gets unique dialogue when you encounter it and vanishes after the fight, though it isn't quite an OptionalBoss since it lacks boss music, can be dodged completely while still getting the item boxes it guards, and is extremely weak. However, dying to it doesn't cause a game over and instead leads to a cutscene where the Apprentice runs off to get promoted into a Snifit by Booster; returning to the area afterwards spawns another Apprentice waiting to be promoted, and this can be repeated for up to five Apprentices. Each one you lose to appears in Booster Tower as an NPC.

* In ''VideoGame/SuperMarioGalaxy2'', there are quite a few examples in the game. Among others, there is only one Spiky Piranha Plant at the end of Sky Station Galaxy's second stage, a single Jammyfish in the middle of Cosmic Cove's second mission, Cluckbooms, Pokey Sprouts, and Rhomps only appear in the first mission of Slipsand Galaxy, and Kleptoads only appear in a Hungry Luma planet in Hightail Falls Galaxy. Magmaws only appear in the Melty Monster Galaxy on one planet.

** And a solitary Chain Chomp in Bob-omb Battlefield which you must set free to get a star.

** The Apprentice is a variant of the Spookum enemies found in Booster Tower (same color, different stats and spells), and only shows up in a secret path of Booster Pass. It gets unique dialogue when you encounter it and vanishes after the fight, though it isn't quite a BonusBoss since it lacks boss music, can be dodged completely while still getting the item boxes it guards, and is extremely weak. However, dying to it doesn't cause a game over and instead leads to a cutscene where the Apprentice runs off to get promoted into a Snifit by Booster; returning to the area afterwards spawns another Apprentice waiting to be promoted, and this can be repeated for up to five Apprentices. Each one you lose to appears in Booster Tower as an NPC.

** Chapter 2-2 features two Gnips and one Gnaw, Merlee's {{invincible|MinorMook}} pets that throw the current character out of her mansion if they grab them. Chapter 2-4, Merlee's Basement, features one Atomic Boo, [[DegradedBoss heavily downgraded]] from its BonusBoss fight in ''The Thousand-Year Door''.

* The first ''VideoGame/MarioParty'' has strange-looking Spike Koopas, which appear only in the MiniGame "Key-pa-Way" and nowhere else in the series.

* While Chain Chomps show up very frequently in the Galaxy games, their smaller baby variants only show up on a single planet in Dreadnought Galaxy.

** The cannons from which the Bullet Bills come from, which is in many levels in [=SMB1=] and [=SMB3=], only appear in the seventh Special World level, Outrageous, and the first room of Sunken Ghost Ship.

** In Cherry Lake, you fight a Pry Guy in order to retrieve the journal he stole from Justice Toad. Despite having his own set of dialogue and unique stats in battle, it's unlikely that you'll see more than two of his quotes as he's not very strong and he's only fought in that instance.
** Similarly, there's Laundry Guy, a one-off enemy from Vortex Island. He fights Mario using a magazine.

** Gelato Beach's second mission marks the only appearance of the Plungelos, red Cataquacks with plunger-esque feet.

** Bowser's Castle has ''three'' examples: The Ninji enemy from ''VideoGame/SuperMarioBros2'', which shows up in the last hallway. There are also Mechakoopas seen in one of the selectable paths (door 3), in the aforementioned last hallway, and during the final battle. Finally, there is a gold-colored Bowser statue in one of the selectable paths (door 7); unlike the common stone statue which shoots fireballs at Mario or Luigi, this one jumps towards them and cannot be stepped onto.

** Most Snifits in the game are grey or green, and stand still without moving from their places, or pink, and move about but turn around when they hit a ledge. A single Red Snifit shows up in one room of 3-3, and will jump down at ledges to pursue the player. It was the former {{Trope Namer|s}}. Despite this, most subsequent appearances of Snifits in Mario games and media have had them be red by default.

** Normal Shy Guys are abundant in Bowser's Snow Fort, but the ones found with the Traveling Toad are not, and for good reason - [[BossInMooksClothing they have 120 HP, ten times much as normal Shy Guys, and stronger attacks than anything else in the area.]]

** The Amazy Dayzee is found only in one spot in the Flower Fields and is randomly generated to be there about 10% of the time. The rest of the time, it's a normal Crayzee Dayzee. [[BossInMooksClothing It is also ridiculously strong]] and likes to run away as soon as possible, but if Mario can defeat it before it runs or he dies, the Amazy Dayzee will provide a mountain of experience points.