mtg innistrad double feature card list Slogurk, the Overslime When it attacks s:dbl c=w · Scryfall Magic:

A mono-blue Merfolk for three mana, this 2/2 prevents Merfolk you control from being targeted by spells or abilities controlled by your opponents

While Khorvath suggests you should also be running Knights, I believe the version of this deck that hits hardest focuses on Dragons

There was a lot of theorycrafting in the cEDH community that focused on how to know what number to pick in order to draw the most cards

You cast any of the three spells you wish to cast for free while this scheme's ability is resolving

However, its the regional exclusivity and premium presentation that mostly drive the price far above the more rainbow-friendly Chocobo variants