World of Goo Wiki
The yellow gears that primarily shatter Beauty Goo and Ugly Goo that also break apart Goo structures in Beauty School

Gears are stage elements found in the video game World of Goo. They can destroy legs of Goos (allowing to detach normally nondetachable structures) and shatter Beauty Goo and Ugly Goo into several pieces. But unlike blades, they don't usually kill Goos themselves.

Some gears, especially in Chapter 4 are actually blades that merely look like gears, and there are some gears will only kill certain types of Goo, such as the blades in Graphic Processing Unit.


The gears that do not break apart Black Goo in Graceful Failure

There are several different types of gears that have functional as well as physical changes.