Yashichi

Yashichi is a spinning blade that appears in Super Mario Land 2: 6 Golden Coins in the Mario Zone. Two of them appear on Mario Zone Area 1, where they spin on tracks, damaging Mario if he touches it. They cannot be destroyed by fireballs, but can be destroyed by Green Shells.

Trivia

 * Their name seems to come from similar-looking symbol used in many Capcom games.