From the Super Mario Wiki
Revision as of 15:57, 12 April 2012 by Marshal Dan Troop
Buster Beetles are bipedal, strong, and quick moving Buzzy Beetles that throw Ice Blocks at Mario and Luigi in Super Mario Bros. 3. They can toss a block back at them or simply jump on their heads to defeat them. When one of the plumbers stomp on their heads, they immediately get defeated instead of staying in their shell like Buzzy Beetles. They appear in most underground cavern levels, especially in Ice Land.
For the most part, they present no real threat, except in close quarters, where their speed and throwing abilities can make them difficult to dodge. Unlike most other members of the Buzzy Beetle family, Buster Beetles are not impervious to fireballs.