Spike (Yoshi's Story)
From the Super Mario Wiki
Spikes are creatures appearing in the game Yoshi's Story. They are sentries of sorts, each one jumping back and forth in one small area of ground and guarding it, or merely standing in one place and periodically leaping straight up. They seem to be made of some gold-colored metal (making tiny sounds as they jump), have large, sharp, cone-shaped protrusions that form the tops of their heads, and are indestructible. They are found only in the levels Bone Dragon Pit and Magma Castle.