From the Super Mario Wiki
Spindel is a type of Thwomp that appeared in Super Mario 64. It is a cylindrical creature made of stone that continuously rolls over the same stretch of territory. The name "Spindel" comes from the word spindle, which is the part of a spinning wheel that holds the yarn that is being spun. Spindel also resembles a giant cylinder with a thread of yarn spun around it, but with a face. It may be a precusor to the Rhomps that appear in Super Mario Galaxy 2, as Rhomps are alive and Spindel is mummified like the Grindels.
Spindel as it appears in Super Mario 64
Spindel appears exclusively in the pyramid of Shifting Sand Land, where it can be found rolling back and forth in one section of the pyramid. There is a safe spot where Mario can hide to avoid being squished.
Spindel in the pyramid in Super Mario-Kun
Spindel appears in volume 16 of the Super Mario-Kun manga. It tries squashing Mario and the Bob-omb Buddy accompanying him, but fails and crashes.
Names in other languages
|Portmanteau of don (colliding sound) and guruguru (turning around something, now for round shape).
||From Walze (barrel) and the name Walter
- ^ Super Mario 64 Player's Guide, pages 12 & 71