I grew up with an aroma that used to be a regular part of the ambiance in my house. It was hot Plastigoop.
Like most kids on my block, I had a Mattel Thingmaker. And, like many of my toys, it would never be sold in today's litigious society. It had an oven that got STINKIN' HOT! And another familiar sight was burns on the hands and arms of my friends and myself. We didn't care. We were making some incredibly cool flexible rubbery toys.
Thingmakers produced many flavors of toys. I owned a Fright Factory. It made third eyes, scars (to add to the real ones caused by oven burns ;-), skeletons, bones that clipped to your nose, and the ultimate: shrunken heads. The shrunken head even had hair you could attach to it!
But what made it megecool was the fact that you could swap molds with your friends and make other stuff, like Creepy Crawlers (snakes, lizards, newts, bugs), Creeple People (ugly little dudes that lived on your pencils), and Fighting Men (soldiers). The Fighting Men would let you stick little wires inside, so you could bend them into fighting poses! But you would always run out of wire, so you ended up with fighting men who just stood there like scarecrows.
Like so many of my other childhood treasures, they sell for big bucks on eBay now. Check out This guy's collection