Gray Rock

Gray Rocks are obstacles in Mario & Luigi: Superstar Saga. They are found throughout the Beanbean Kingdom, serving as roadblocks for Mario and Luigi. They can be destroyed by Super Hammers and Ultra Hammers (which are forged by the Hammerhead Bros. at their home in the Beanbean Castle outskirts), but not regular hammers. A Gray Rock blocks the entrance to Teehee Valley and must be destroyed to proceed.

In Mario & Luigi: Superstar Saga + Bowser's Minions, they are a lighter shade of grey, and are only differentiated from the weaker rocks by being far less cracked, only having a small chink.