In the Swim! Fun and Sun Fashions

The comic.

In the Swim! Fun and Sun Fashions is a single-panel comic from the Super Mario Bros. #4 edition of the Nintendo Comics System series of comics. It is framed as an advertisement for various swimwear from Apook™ Corp.

The advertised swimwear include:

• Swimming trunks for Sledge Brothers, which come in two colors (Turtle-Green and Tortoise-Shell) as well as with optional hammer holsters.
• Spandex bottoms for Stretchs, apparently designed to allow them to twist and stretch their bodies comfortably.
• A line of "budget swimwear" for Spiny Cheep-Cheeps, which appears to actually be a flour sack with holes in it for the Cheep-Cheep's spines.
• The "Baggie" swimsuit, designed for Shyguys. The swimsuit is merely a bag which covers the entirety of the Shyguy's body, though it still wears its mask outside the bag.