Check the listing for details. Marcus the Worm Keychain. Color: Beige, Condition: New, Made in United States. Listed at 12.99 USD. The Marcus the Worm Keychain is a modern collectible featuring a beige PETG material design inspired by the popular character family of Marcus the Worm. Made in the United States, this keychain is perfect for animal-themed collectors looking for a unique and fun addition to their keychain collection. With its modern era design and quirky animal theme, this keychain is sure to stand out and make a statement. It is my design and 3-d printed by me out of PETG.The Marcus the Worm Keychain is a modern collectible featuring a beige PETG material design inspired by the popular character family of Marcus the Worm. Made in the United States, this keychain is perfect for animal-themed collectors looking for a unique and fun addition to their keychain collection. With its modern era design and quirky animal theme, this keychain is sure to stand out and make a statement. It is my design and 3-d printed by me out of PETG.