Mine
The title of this article is conjectural; an official name for the article's subject has not been found, so it has been given a fitting title by the editors. If an official name is found, then the article should be moved to its appropriate title.
Floating Mines first appeared in Super Mario World as spiked balls that drifted in the water in various levels. They follow the current continuously and pulsate with spikes. Yoshi can step on their spikes harmlessly and a Starman can defeat them. In the Sunken Ghost Ship, many are in freefall, making it difficult for Mario or Luigi to move around. They can also be eaten by Yoshi.
The Mines reappeared in Super Mario Land: 6 Golden Coins as a spiked ball spinning around a bubble in the final stage of the Mario Zone; these Floating Mines behaved identically to Ball 'n' Chains and Roto-Discs.
