Stretch Armstrong was first sold in 1976, and is still available today. The dolls were latex skin filled with a thick gel that would give it a little bit of shape inertia.
There was nearly a Stretch Armstrong movie, although the project ultimately fell through. I personally feel that is probably for the best.
Here is an unstretched Armstrong.

And stretched.

I case you’re wondering, you can fill stretch with 25 gallons of water before he breaks.
He was filled with corn syrup no joke
So, like any typical American kid.
Yup, corn subsidies do wonders
I remember there was a badguy/nemesis who was full of packing styrofoam, and you used a pump to vacuum the air out and make him moldable/stretchable.
I feel like his spiritual successors are Plasticman, Richard Reed from Fantastic 4, and Mrs. Incredible (with delicious feminist implications).
I was also just thinking how plastics is a nice contrast to AI. People keep trying to convince us to use AI, but we don’t want to because we know it makes us stupid and we know it is absolutely unreliable. But plastics, man, plastics were fucking everywhere all at once, because they were actually useful in a lot of different contexts.
Edit: Looks like Plastic Man (1941) predates Stretch (1976), but I mostly know Plastic Man from Saturday Morning.
Yet, Kenner never marketed him as a superhero license from Marvel.

There were the muscle men minatures too that came out in the 80’s but yah the incredibles movie seems to be the current equivalent.
Resistance bands, for kids
I remember this, that and the miniature muscle men made out of a similar plastic.
Millions of Unusual Small Creatures Lurking Everywhere! I loved those things. Never understood the wrestling tie-in, but whatever.
Yah I forget where that theme was from but I thought it was a play on the popular he man tv series…but in miniature form. Micro machines were also super popular back then too.
That guy sure could talk fast!
He certainly could lol




