Cards like Elven Ambush double your creature count, while Lys Alana Huntmaster makes your Elf creature spells a two-for-one, giving you an Elf token every time you cast an Elf card
You can drop this on turn three, sacrifice a two-drop artifact dork for two cards and two mills, sac it to Goblin Welder to swap for something you just milled or what you sacrificed, and then swap the sacrificed or milled card on turn four for this to keep
If you control Harold and Bob, you'll return it to the battlefield when it dies while it's a creature
In other words, the Superhive is all you need for your next Game Night
From what I've been hearing it was originally started as a kickstarter business printing foil playmats (which I must admit would be pretty cool)
The buy-in is just too high