It's a series that was cancelled and replaced with another Avengers cartoon after the 1st Avengers movie came out. The 42nd episode is called Assault on 42. 42 is a prison for supervillains in this story. The prison is located in the Negative Zone, which is sort of an alternate universe where the laws of physics are different. The setting was created by Jack Kirby.
"What was it created for? Jack Kirby has been credited in creating the Negative Zone. He said he liked experimenting with gimmicks and wild ideas and technology/ideas/concepts/things we’d see in the future. Just going big with ideas and possibilities. That’s how he came up with Ego and the Negative Zone, among other things."
Ego was a living planet in one of the Guardians of the Galaxy movies, I think. I tried to watch the cartoon, but didn't really pick up on anything relevant other than the alien bug creatures maybe being a symbol of something. Supervillains = superspreaders maybe?
Follow up: In the comics the prison, 42, first appeared during Marvel's big Civil War crossover event of 2006. Its nicknames are Fantasy Island, and... Wonderland.