Skeleton Bee

A Skeleton Bee is an enemy in Super Mario Land 2: 6 Golden Coins that appears in Area 4 of the Tree Zone, and like Bee and Būichi, it can only be found in this particular stage. The Skeleton Bee is tougher than their non-skeletal counterparts, as they can come back to life after Mario defeats it. Doing a Spin Jump or using a Star are the only ways to defeat them permanently. Also like their counterparts, they appear out of the hives in the background and move very slowly. In official artwork, they appear to have a normal, non-skeletal body; however, in gameplay, the bottom half is able to be seen through as if they are completely composed of bones.

Super Mario Land 2: 6 Golden Coins

 * Virtual Console manual: "This bee has become a skeleton. Even if Mario stomps on this bony bumblebee, it'll come back to life."