Millstone is the origin of the trading card game "milling", which is basically to moving cards out of your opponent's deck into somewhere less useful (typically the graveyard), and denying them resources that they could use
Froslass has gone far too long without receiving something to celebrate, but this card might be the perfect gift for Froslass fans
Marcy: There are a lot of Izzet decks that want to abuse this card, and I think with some easy set up, it could potentially do a lot of copying shenanigans, but it is a little annoying that the card cannot exile cards itself
Grab 2 Jumpstart packs, shuffle, and youre ready to rumble
There are exceptions to this rule, of course
This card features a humanoid mouse striking a martial arts pose reminiscent of the legendary Bruce Lee