Mine

Mines (either capitalized or lowercase) are Spike Ball-like bombs that first appear in Super Mario World. Despite their name, they are not always shown to be explosive.

Super Mario World
In Super Mario World, Mines, also referred to as Floating Mines, first appear in Yoshi's Island 4 as spiked balls with a wooden texture that drift in the water. They follow the current continuously and pulsate with spikes. Yoshi can step on their spikes harmlessly and eat them, and a Super Star can defeat them. In the Sunken Ghost Ship, many are in free fall, making it difficult for Mario or Luigi to move around, and slowly rise to the surface when landing in the water.

Super Mario 64 / Super Mario 64 DS
Mines, simply called bombs in Super Mario 64 and also called spiked orbs in the Player's Guide and Super Mario 64 DS, play a vital role in defeating Bowser. In the final arenas of Bowser in the Dark World, Bowser in the Fire Sea, and Bowser in the Sky, where the bombs surround the arena, Mario, Luigi, or Wario has to throw Bowser into one of the bombs to defeat him (three in Bowser in the Sky). If the player jumps into one of the bombs, it will blow up and they will take two wedges of damage.

There was also going to be a smaller, water-based variant, but it was cut out from the final.

Mario's Time Machine
In Mario's Time Machine, unexplosive mines appear as obstacles while Mario is surfing around. In the PC version, hitting a mine causes Mario to lose only one mushroom, whereas in the SNES version, hitting a mine causes Mario to lose all of them.

Wario Land: Super Mario Land 3
In Wario Land: Super Mario Land 3, small mines appear as somewhat common obstacles. They can be found on the ground, where they can be picked up, or floating in underwater, where they can interrupt a Body Slam. If interacted with, they proceed to flash and then soon explode, causing damage. The Pecan enemy can also spit mines that sink and automatically explode.

Mario Party 2
In Mario Party 2, mines appear in the miniame Deep Sea Salvage, where they are thrown in an arc among Coins and Coin Bags by a Hammer Bro on a ship. Like the other objects, they sink directly downward when they land in the water. They explode if they hit a player, stunning them for several seconds. Unlike the other objects, they also explode if they touch the ground on either side of the screen.

Mario Party 3
In Mario Party 3, mines (referred to as bombs) appear in the minigame Cheep Cheep Chase, where they are in the way of the players, who are being pursued by a giant Cheep Cheep. To get around them, the players must dive.

Mario Party Superstars
Mines reappear in Mario Party Superstars, reprising their roles in the Cheep Cheep Chase minigame.

Donkey Kong Country 3 (Game Boy Advance)
In the Game Boy Advance remake of Donkey Kong Country 3, floating mines appear in the "Disarm" mission of Funky's Rentals. The Kongs must take four mines from a Kremling one at a time, and have them safely detonate in a designated space.

Luigi's Mansion 3
Several types of mines appear in Luigi's Mansion 3. In the Boilerworks, mines remain still and flash red when approached, exploding after a seconds. In the ScreamPark minigame Coin Floating, two types of mines appear. There is a normal type resembling a Spike Ball, and a homing type that acts as a bomb. The later moves toward the nearest player, and when close, it flashes red and eventually blows up. Their explosion can pop Luigi's inflatable duck boat and make him drown, losing 20 HP. In the ScreamPark minigame Floaty Frenzy, mines are periodically dropped onto the field to block certain ways, and explode by themselves after some time passes or if touched by a player.