There have been 7 Spellbook exclusive promo cards released to date; dating as far back as MetaZoo’s first Kickstarter in 2020.
Every set since has received an exclusive Spellbook promo of its own, putting on a display of some of the most notable Beasties from its set.
You will notice that the card name used to correspond with its set name, but has since grown to have full card names of their own; inclusive of the set name.