A Pokemon fan and artist has designed an impressive Gigantamax form for Shuckle. As one of the biggest media franchises in the world, it's really no surprise that Pokemon has inspired near-endless fan art.
The franchise's most popular Pokemon are often featured in such art. There is a ton of art featuring Pikachu, Charizard, Mewtwo, and the franchise's other heavy hitters, though some artists make it a point to include underrepresented Pokemon in their pieces as well.
Shuckle would definitely fit into the category of underrepresented Pokemon. A Bug/Rock-type from the second generation of Pokemon games, Shuckle has no evolution line whatsoever.
This means that not only does no Pokemon evolve into Shuckle, but Shuckle is incapable of evolving into anything either. Unfortunately for any fans of Shuckle, this extends to the franchise's various gimmicks that have been introduced over the years, so Shuckle doesn't have an official Mega Evolution or Gigantamax form.
While an official version still doesn't exist, artist Dude0720, who previously created a regional variant for Torkoal, took it upon themselves to create their own take on what a Shuckle Gigantamax form would look like.