Looks like this might have been faked: https://m.reddit.com/r/pokemon/comments/5lc1lj/remember_the_guy_that_did_the_cosmog_sweep_a_few/

You can do better than that.

Which in this case are completely justified by the outright lie in the headline.

Uh yeah, sorry to rain on your parade, but Cosmog didn’t actually do anything. It was Nihilego’s Toxic Spikes that did the actual destroying. He actually just sent Cosmog out there to stall the other trainer constantly while the Toxic Spikes poisoned the other Pokemon and did all the work for him. This is actually…

So he eventually won by finding one person who didn’t know what he was doing to battle with?

No, I don’t, because this is a weird thing that people trot out about Gen 1 Pokemon despite absolutely not being true.

Magnemite? Porygon? Jynx? Koffing? Muk? Voltorb? Plenty of inanimate objects in Gen 1 of Pokemon. It’s only natural that with further generations there’s more Pokemon based on other objects and…

I too remember when the Pokemon were based off of animals like:

Yes. 3D Fields in the main games were introduced in Generation 6.

It’s actual name is cosmog. In the game, the cosmog Lillie owns is nicknamed Nebby. Also, it’s a nebula.

Mr. Mime? Cubone? Nidoran? Lots of Gen-1 weirdos.

He didn’t beat the team with cosmog... He beat the team with the setup. Cosmog was just a punching bag while the setup did it’s job. Cosmog could have been replaced with a magikarp.