Swamp Thing was heavily marketed in the early 90s.
The cartoon spawned an array of merchandise, from sleeping bags to sidewalk chalk.
HERE IS THE PROOF!
These one sheeters were handed out at trade shows and ‘industry’ events. They were used to entice investors and companies that fabricate/distribute everything from… sidewalk chalk to you know, sleeping bags. Artist Alfredo Alcala provided concept sketches and style guides to help establish the look of the artwork used in the materials and products.
Below is another promo piece. This was found in an entertainment magazine. not the magazine titled entertainment, but an industry magazine promoting upcoming marketing opportunities and upcoming movie/tv releases.