“Revolt in the Fifth Dimension” is a 1967 episode of the old Spider-Man cartoon which was directed by a then 25-year-old Ralph Bakshi. It was in part fashioned from reused animation cells from an episode of a Canadian cartoon called Rocket Robin Hood that Bakshi had recently produced. Spider-Man was simply substituted for Rocket Robin Hood on the animation backgrounds. This el cheapo production method ended up yielding an episode of Spider-Man where the plot was more Doctor Strange than the kind of stuff everyone’s friendly neighborhood webslinger usually got up to.

The synopsis from TV.com:

A dying scientist from the destroyed planet Goth in the deceased galaxy of Kamosah must land his crippled spaceship on Earth and, before expiring, entrusts Spiderman [sic] with a tiny but encyclopedic library of information, including the secrets of a dimension of living thought, whose one-eyed, skeletal ruler, Infinata, wants this information destroyed.

 

 
For reasons no longer specifically recalled, this was the only episode of the Spider-Man cartoon series that ABC either chose not to air in the first place, or when they repeated the series, although it lived on in syndication for years afterward. Reports are conflicting.

The possible reason they didn’t transmit (or rerun) this memorable episode might be how acid-tinged and druggy it is—not that the overt death theme and flying sperm wouldn’t have been enough!

It’s worth recalling that Bakshi, who famously animated Robert Crumb’s horny Fritz the Cat, the race fable Coonskin and the first big screen adaptation of Lord of the Rings, made a controversial episode of Mighty Mouse in the 1980s where the main character is seen charging up for battle by inhaling a “special powder” out of a flower!