(Alternatively title: Rust Monster Begins.)
From NerdNYC dot com:
Evilyn loved dinosaurs as a little kid. Her dad bought her cheap bags of plastic dinosaurs made in Hong Kong from the local dime store:
Now even as an 8 year old kid, Evilyn was some what of a dinosaur expert. She would consume book after book on all things dinosaur. So when she found a "dinosaur" in the bags her dad bought her that looked like a clawless giant lobster with a propeller for a tail... she knew something was up!
Nonetheless she loved playing with it! Shrimpy, her name for it, vexed her for years, providing hours of curious daydreaming imagining what the hell Shrimpy was.
3 years later, Evilyn plays Dungeons and Dragons for the first time, the Monster Manual being her favorite part! Where to her surprise she finds:
What? Shrimpy is a rust monster?
To this day the rust monster is her favorite D&D monster. She still has Shrimpy at her parents house.
Today she shared this story with me. So of course I ran online to see what I could find. And find I did!
The rust monster's appearance is based on a plastic toy that was sold in toy stores during the 1970s and 1980s in cheap bags of plastic monsters and dinosaurs. Gary Gygax wrote about the inspiration for the rust monster: "When I picked up a bag of plastic monsters made in Hong Kong at the local dime store to add to the sand table array ... there was the figurine that looked rather like a lobster with a propeller on its tail ... nothing very fearsome came to mind ... Then inspiration struck me. It was a rust monster." —Gary Gygax