Loyal Warhound Weve seen a card somewhat like this in the past, with Knight of the White Orchid
The other nice part about these mill options is that we end up with a decent curve of creatures that we barely care about after their ETB mill triggers resolve
Since SAR cards are the rarest of all while UR cards rank second, SAR cards are almost always more expensive than their UR counterparts

Ambrosia Whiteheart Apothecary White Bringer of the White Dawn Circle of Protection: White Elrond of the White Council Flowering of the White Tree Gandalf the White Gandalf, White Rider Gather the White Lotus Knight of the White Orchid Minwu, White Mage Nine-Tail White Fox Order of Whiteclay Order of the White Shield Rosa, Resolute White Mage Rune of Protection: White Sacred White Deer Saruman the White Saruman, the White Hand The Destined White Mage Uglk of the White Hand White Auracite White Dragon White Glove Gourmand White Knight White Lotus Hideout White Lotus Reinforcements White Lotus Tile White Mage's Staff White Mana Battery White Orchid Phantom White Plume Adventurer White Scarab White Shield Crusader White Sun's Twilight White Sun's Zenith White Tiger, Amulet Keeper White Tiger, Ava Ayala White Ward White Widow, Free Agent White Widow, Yelena Belova Whitemane Lion Whiteout Whitesun's Passage Whitewater Naiads

It was also meant to have a playable set full of older cards that can get drafted via Limited 2X2 Draft events