G is for Greengrocer. The Greengrocer is the green morph of the Australian cicada Cyclochila australasiae. These cicadas can be found in south-eastern Australia. They have a large pronotal collar, and if you use your imagination, it looks like they’re wearing a tiny Pith helmet above their eyes.
Here’s a close of up of a Greengrocer (from Bron):
Here’s a box of Greengrocers (from Kevin Lee):