When you goggle, you stare with wide-open bug eyes. You might goggle at a monkey riding a unicycle down the main street of your town.
You may have heard of goggles — those large, plastic glasses that you use to protect your eyes while you are skiing or using a blowtorch. You might look like you are wearing goggles when you goggle at something. If you are looking for a new way to say "What are you looking at?!" Try: "What are you goggling at?!"