Spiny Beetle

Spiny Beetles first appeared in A Link to the Past, where they could sometimes be found sheltering under rocks or bushes. By using the Power Glove or Titan's Mitt, Link could remove the rock from the beetle. Once the beetle's cover is blown, it scurries around, dropping green rupees, then disappears. The Sword can be used to kill Spiny Beetles lying under grass or bushes for protection, but the Power Bracelet are needed to remove stones and skulls on top of some Spiny Beetles before they can be harmed in Link's Awakening. They can be spotted easily as the rock or patch of grass they hide under will be a little crooked. Quote from The Legend of Zelda: The Minish Cap Spiny Beetle figurine:

"Appears in various areas. They hide under common rocks and grass be careful, because they can pop out when you least expect it!"

In Link's Awakening there also exists similar Spiny Beetle's that hide under skulls. This version of the enemy acts completely identical to the ones that hide under stones. First the skull must removed with the power bracelet before they are vulnerable.