Enter the Unknown Enter the Unknown is quite comparable to the fan-favorite Explore, and there are many instances in which a +1/+1 counter/surveil 1 is worth as much as the draw and definitely deserves more consideration
However a few do have "practical" uses - here are some examples: The particular card you reference, Garruk the Slayer, was created for the Magic 2015 prerelease and is used in a variant where one player plays normally and the other plays as Garruk
Plus, many of the decklists provided come from my own personal collection, and I only have so many Triomes and fetch lands, so cut me some slack
Pokmon Single Cards At the very base are Pokmon single cards
Merfolk have just 9402 decks over at EDHREC.com, which is a top 20 archetype at 17, but pretty low considering how often they were played in the old days
Powerful creatures that naturally create tokens are one of the best ways to utilize Mirrormind Crown