Gunk Slug
Creature — Slug
When Gunk Slug enters the battlefield, create three Gunk token cards and shuffle them into target opponent's library. (Gunk is a colorless sorcery card with no mana cost that has cycling 
.)
Illustrated by
Mystery Booster Playtest Cards 2021#43RareEnglishLegality
Rulings
Unlike a normal token, a token card doesn’t cease to exist in a zone other than the battlefield. It’s both a token and a card. It can move between zones any number of times and continues to exist for the rest of the game.
If a token card is put into a hidden zone, you must use a supplementary token card with a Magic card back to represent it. Since these don’t exist yet, you may need to be creative.
For effects that look for or modify the creation of tokens, creating token cards isn’t the same as creating tokens.
A Gunk token card is a colorless Gunk sorcery named Gunk with cycling . It has no mana cost, so you can’t normally cast it. It has no spell abilities, so if you do find a way to cast it, it won’t have any effect.
Cycling means “, Discard this card: Draw a card.”